DOCUMENT RESUME
ED 111 639 SE 019 339
AUTHOR. Elmer, James D. TITLE Theory of Aircraft Flight. Aerospace Education II. Instructional Unit I. INSTITUTION Air Univ., Maxwell AFB, Ala. Junior Reserve Office Training Corps.
REPORT NO k. AE-2-7201 PUB DATE Feb 75 NOTE 73p.; For the accompanying textbook see SE 019 338
EDRS PRICE MF-$0.76 HC-$3.32_)-Plus Postage, DESCRIPTORS. *Aerospace Education; *Aerospace Technology; Course Organization; Curriculum Guides; *Instructional Materials; *Physical Sciences; *Physics; Secondary Education; Teaching Guides; Unit. Plan IDENTIFIERS *Air Force Junior'ROTC
ABSTRACT This publication provides guidelines for teachers using the Aerospace Education II series publication entitled "Theory of Aircraft Flight." The organization of the guide for each chapter is according/to objectives (traditional and behavioral), suggested outline,,orientation, suggested key points, suggestions for teaching, instructional aids, projects, and further reading. A separate sheet is attached at the end-of each chapter for teacher ideas for improvement of the chapter. Specific suggestions have been made ihfOughout the guide for the ,major concepts. Page references corresponding to the textbook'are made where appropriate.(PS)
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*********************************************************************** Documents acquired by ERIC include many informal unpublished * materials not available from other sources. ERIC makes every effort * * to obtain the best copy available, nevertheless, items of marginal * * reproducibility are often encountered and this affects the quality * * of the micrpfiche and hardcopy reproductions ERIC makes available * * via the ERIC Document Reproduction Service (EDRS). EDRS is not * responsible for the quality of the original document. Reproductions * * supplied by EDRS are the best that can be made from the original. *********************************************************************** r P
U S DEPARTMENT OF HEALTH, EDUCATION & WELFARE NATIONAL INSTITUTE OF EDUCATION AE-II-7201 THIS DOCUMENT HAS(TEEN REPRO OUCEO EXACTLY AS RECEIVEDFROM FEBRUARY 1975 THE PERSON OR ORGANIZATIONORIGIN ATING TT POINTS OF VIEWOR OPINIONS STATE() DO NOT NECESSARILYREPRE A SENT OFFICIAL NATIONALINSTITUTE OF EDUCATION POSITION OR POLICY
I
AE-II
INSTRUCTIONAL UNIT I
THEORY OF AIRCRAFT FLIGHT
t
/
WRITTEN BY >,.
LT COLONEL JAMES D.,ELMER CHIEF, HIGH SCHOOL CURRICULUMDIVISION DIRECTORATE OF JUNIOR PROGRAM
2 FEBRUARY 1975
AE-II - COURSE CONTENT
COURSE LEVEL OBJECTIVES- Each student should:
a. Know the major factors which affect aircraftdesign.
b. Know how aircraft engineers have taken advantageof advanced technology to make aircraftmore efficient.
c. KnoW the Oajor design characteristicsof aircraft engines.
d. Know the effect advanced aircraft enginedesign has on improved air travel.
e. Knrow the basic elements of air navigation.
f. Know how to use the simpler aids to airnavigation.
g. Know the status of civil aviation.
h. Know the effect civil aviation hason our society and the ToTa-lems yet to be solvdd.
i. Understand the role-of militaryaerospace in our society.
1110 INSTRUCTIONAL UNITS IN AE-II:
I. Theory of Aircraft Flight
II. Propulsion Systems for AircrafL
III. Air Navigation
IV. Civil Aviation and FacilitiesA 4 V. Military Aerospace,,,, I
3 I FEBRUARY 1975 INSTRUCTIONAL UNIT I
THEORY OF AIRCRAFT FLIGHT
\INSTRUChONAL UNITOBJECTIVES - Whenthe book is completedeach student 1/4should:
a. Be'familiar with man's ea 1)', attempts to fly.
b.. Know the basic physical laws which pply.to aircraft flight.
c. ,Know the properties of the atmosphere which.areimportant to aircraft flight.
d. 1Know the forces acting uponan airplane in flight.
e. Be familia'r with aircraft stability andhow it is affected by aircraft controls.
f. Know how 'aircraft engineers have takenthe basic physical laws 4 and the charac er'istics of the atmosphereinto account when designing aircraft.
g. Knowthe'importa ce olipircraft instrumentsto safe flight.
-,INSTRU6TIONALUNIT I CHAP RS /
Page 0
I. Aerodynamic Forces I-1
II. Properties of the Atflp Phere 1-12
III. Airfoils and Flight 12i,9
IV. Weight). Thrust, and Drag 1-29
V. Aircraft Motion and Control 1-38
VI. Aiircraft Structure 1-47
VII. Aircraft Instruments 1-57
4 FEBRUARY 1975 j
CHAPTER I- AERODYNAMIC FORCES
This chapter introduces theunit andplaces man's attempts to fly in historical perspective. The student should realiie that the Wright brothers' achievementdepended on theex- perience of many centuries..Once the student has thissense of history firmly in mind, hecan then examine the evolution of certain other physical laws in orderto see how these laws affect aircraft in flight. Finally, he can takea quick look at an aircraft in flight in orderto see how both history and physical laws help explain why theaircraft stays aloft.
OBJECTIVES:
a. Trdditional ':Eadl'Ittideiii should:
(1) Be familiar with man's early attemptsto fly.
(2) Know Newton%s Laws of Motion.
(3) Know how Bernoulli's Principle appliesto aircraft flight.
(4) Be familiar with the forces affectingan aircraft in flight.
b. Behavioral- Each student should be able to:
(1) Give at least three examples of man'searly attempts to
fly. \10 . 1 (2) -State each of Newton's Three Lawsof Motion and give an example of each.
(3) Describe how Bernoulli's'Principleapplies to aircraft flight.
(4) Name each of the four forcesthat affect an aircraft in flight.
2 SUGGESTED OUTLINE:
a. Man's early theories and myths aboutflight.
(1) Grecian Legend- an attempt to explain why birds fly and man does not.
(2) Archimedes' Experiments- concluded that things lighter than air will float in the atmosphere.
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FEBRUARY 1975
b. Early manned flying attempts .
(1) Pre-C4stianChinese Period- Chinese man-flying kites; battle observation.
(2) Leonardo da Vinci- designed forerunners of the parachute and a helicopter which lackeda power source; ideas dormant until recently.
(3) Bird observation- observing birds'in flight proved to be the clue to the secret of flight. Z7 4 (4) George Cayley 19th Century Englishman;built the first true model glider.
c. Twentieth Century advances
(1) Emergence of the combustion-engine.
PriMary source of Power in the 20thcentury.
(b) Samuel Langley- one of first to build a powered aircraft.
(2) Introduction of the, dirigible- a steerable airship; competed with heavier-than-airaircraft for superiority in the early part of century. .
(3) Wright brothers- Dryille and Wilbur,.combined all the ous knowledge to make the first.successfulcontrolled,
pprilgo ed, heavier-than-air aircraftflight: . d. Physical laws Oderlying flight
(1) -Bas4cprinciplesof flight; heavier-than-air craft fly because their airfoils lift and support'theirweight in flight as thrust is created whichovercomes- the resistance .of air (drag).
(2)' Sir Isaac NewtOn's(1642-1727) Laws of Motion
LaW of Inertia- "a body continues in its state of rest or uniform motion in a st'raightline unless a unbalancieforce actson it."
(b) "The acceleration ofa body is directly proportional to the force exerted on the body,is inversely pro- portional to the force exertedon the body, is inversely proportional to themass of the body, and is in the same directionas the force."
1-2 FEBRUARY 1975
(c), 'When= er one body exerts a forceupon'a second y, the second exerts an equal and opposite force
upon the first body." .
'(3) Teims and explanationSof-Newton's
(a) First Law.
1. Acceleration the change in speed per unit of time We_given direction.
2. Velocity - the rate of motion ina given direction.
(b) Second Law. ,
, 1. Force - Power or energy which poSsessesboth magnitude and direction and is exertedagainst a material body in a given direction.
2. Mass - quantity of matter ina body.
3. Weight --pull of gravityon that quantity of, matter.
(c) 'Third Law- for every action there must be an equal and opposite reaction. Ns. (4) Daniel Bernoulli- 18th century SWiss scientist.
(a) Discovered theprinciple that as velocity ofa fluid increases its pressure decreases.
(b) Venturi Tube- narrower in the 'middle than at ends;" this restriction causesa decrease in pressure- an application of Bernoulli's principle. e. Forces of flight
(1) Lift, weight, thrust, and, drag- opposing forces must be in balance with one anotherwhen an aihraft is straight and level, unaccelerated flight".. 4
(a) Lift - operates toovercome weight.
(b) Weight- force pulling the aircraft toward the earth.
(c) Thrust - force giving motion toaircraft. 1 (d) Drag- force that opposes thrust or forward motion of the aircraft.
I -3 41 I
FEBRUARY 1975
3. ORIENTATION:
The relationship between history and flight science.
% (1) The qrst part'of this chapter revielks the historical developments of man's quest for successful flight, but ..not in the detail or depth pursued iin Aerospace Education I.
(2) The justification for the brief review is toteinfOrceyout students' recall of the historical developments of aviation and various types of flying craft in order that they may gain an understanding as to why men flY. In th'i's manner we -make the transition from the historical development of aviation to the theoretical principles of flight aid the Ph ical laws which govern them.
SUGGESTED KEY POINTS:
(NOTE: Many page references cited in this hapdbook may not contide with the exact pages of your reference books. Many reference books have been revised several times since AFJROTC started in 1966.)
a. We take the student back in history to the myths' *** V-9002, pp 1-4',and legends related to man's desire to fly.We show that there were undoubtedly some grains of ** V-9014, pp / truth and fact contained in them and that the 11-37, pyramid of legends and experiences gradually enable'\ *** V-9156 (19,71 man to realize his dream. ed.), op 6 6-9 * V-9198, b. As man observed the air space around him and,sUch (The Flying natural phenomena as smoke risip and.the flight Machine), pp of birds, he became aware that his basic probleM 1-4 / was to build an airship which was lighter Min a like volume of air.
c: Since satisfactoryptwersources for heavier-than- *** V-9002, pp air craft weren't available, the Montgorlfier 4-8 brothers introduced balloon flight. COptinuous ** V-9014, pp,_ progress and success with balloons reviltaliied 36-69 and stimulated man's interest in flying. *4* V-9156, pp '62940 d. The student should be brought to relnize that ** V-9002, pp the true pioneers of flights were the nineteenth 10)43 century experimenters who lai the real foundation's *** V=9014, pp 78, or controlled, powered, he ler-than-air flight.
I 80-84 *** V-9156, pp- (1) Among these stand ou such notables George 640-4 Cayley who construced the first true model ** V-9157, pp 8-13 glid" and John ntgomery and Otto Lilienthal who recognized the need for an understandihg of bird flight and the controlling of gliders.
1-4 V
FEB ARY 1975
e. The late 19th and early 20th centuries.saw the *** V-9014, pp ,emergence of the combustion engine. Much of its
- 84-88' . development was clouded by history and time. One ** V-9156, pp y of the first to build an aircraft and power it
644-5 . with an internal combustion engine was Samuel -- Langley; Secretary of the Smithsonian Institute.
(1) During the early part of the century we saw ** V-9014, pp 70 -71,' the dirigible balloon'or airship competing 124-125 with heavier-than-air ships for Superiority. ** V-9156, pp 639-40, However, as engine horsepower and aircraft
. 711-12 'design developed, the dirigible lost out due to the advantages of greater maneuverability ** V-9002, pp 13-15 and speed of airplanes.
** V-9005 (1971 ed.) 8 pp 12-13 f, The foresight of the Wright brothers in taking advantage of all previous research and in finally *** V-9014, pp achieving the first successful "controlled," 85-87, 106-109, "powered," and "heavier-than-air" aircraft flight
114-115 . catapulted us into the aeronautical age: ** V-9156, pp 645-6 g. Physical laws underlying flight
1). (1) In this section of our chapter, we deal with the principles of aerodynamics and the physical
. laws that apply to them, The students must ** -43002, pp 38-40 acquire a solid foundation in Newton's Laws ** V-9013, pp 43-4 ,of Motion and Bernoulli's Law of Pressure ** V-9065, pp 13-16, Vifferential before progressing further into 22, 44-5, the subject of aerodynamics.
(2) In applying Newton's Laws to the principles
0 of flight, we will want to consider velocity as the rate of motion in a given direction and acceleration as the change of rate of - motion in a given direction per unit of time. The latter two terms comprise Newton's First Law of motion.
(3) In considering the Second Law .which deals with
*** V-9023I, pp ' force and mass, we think of force.as being 13-16, 20-24 "power" or "energy" which has magnitude and direction and is exerted against a material body in a given direction. Mass is the
quantity of matter in an object. We can then , combine these ideas into a formal statement. "The rate of change of motionof a body is directly proportional to the power or energy exerted against this body, is inversely pro- portional to the quantity of matter in this
. body, and is in ,the same direction as the pOwer or energy exerted against this body."
95 FEBRUARY 1975 %
(4) The Third Law = for every action there must be an,equal and opposite reactionieis essential in arriving at our compositesummary of Newton's Laws. \ ,
(5) Bernoulli's discovery of the principle that as velocity incr &ases, its press! -e decreases is'a primary key to powered combustfble flight. The latter principle is utilizedin the Venturi Tube, an important part of any car- buretor. The Venturi Tube is narrower. in the middle tan it is at the ends. The Venturi effect.,causes fluid passing through such a ube.to speed up as it reaches the middle. iri results in leas energy for the ekertion of essure, causing a decrease in pressure. The effect is known as Bernoulli's Law of,. Pressure Differential.
5. SUGGESTIONS FOR TEACHING: 1
a. Suggested time: 1-2-3 (Translation--if you teach two academic Aeriods per week we recommend you devoteone hour to this sub- ject. If you teach three periods per week you could devote two periods. If you teach four academic hours per week Au could devote three periods to the subject. These "Suggested times" are just that--recommendations. Adjust",the emphasis according to interest and talent-7bothyours and the students'.)
b. Motivation. Bedause the'student has already been exposed to aviation history in his first year,you will have to do'some stage setting to revive his interest for the initial introduction, of the chapter. .If substantial publicor school library facilitiet are a'ailab1e, you might establish a book displaycorner which would cover reading material that would supplement theresource material recommended in your key points. Another possibility is to prepare a bulletin board which depicts the historical, advances in flying craft, but which is also labeled with captioins to show how these advances have extended thduse of the physical principles of flight relative to Newton's Laws of Motion and Bernoulli's4.aw of Pressure Differential.
c. In introduCing the lesson, you should consider the wealthof support materials available for this'text.The 5 minute FAA Film "Kites to Capsules" (see paragraph 6 below) would be an excellent inter st stimulator. If.you are lucky enough to have an opaque p ojector, there are numerous-colorful historical pictures In youreference library books. After you have established' flying as an interesting subject (which.shouldn'tr
. ,
I-6 10 1 1
FEBRUARY 1975
be too hard,to do) you may effectively ask the students.to cotnpare aviation history to what-tnty have learned in other courses. This discussion should include the significance of flight/and the development of the prindiples of flight. Such a discussion should affable you to determine whit your students already know about.the subject. The student discussion can be effectively semarized by recording with the studentsthe stages which depict the'historical.advances.in aviation. NOTE: A pre-test could work well as a mans of determining student knowledge about this instructional unit.
d. Another gobd method is to divide the class intogroups and have each group research, one historical phase. They can 'relate their assignment to the scientific principles of flight when they make their report to the class.
e. Throughout this instructional unit, these are many excellent opportunities to work with other instructors. For example, the instruction on Newton's Laws may be_best accomplished by using the Physics instructor as "a guest lecturer2T-The Chemistry Department Ocould be contacted ,prior to covering Chapter II. For Chapter VI, you may want.to haveyour students do some actual construction. The shop and vocational instructors should be able to offer valuable assistance. Under any, circumstances, your instruction should supplement the instruction received in other classes on the same subject. You will "turn off" your better students Wry quickly unlessyou are aware of'what they have already been taught about -the subject. Use their knowledge to suwlement your instruction.
M f. If at .1 ssible, you should review your plans for the entire unit of instruction prim...to planning projects. 0 For example, kite fl,ying would be appropriate for Chapter Ior III while paper airplanes are an excellent instructional aid for Chapter III. These same paper airplanes can be modified when studying aircraft control in Chapter V. If your students have not made model aircraft in AE-I, constructing models either forPrinciples of Flight in Chapter III or Aircraft.Construction,in ChapterVI would be appropriate. *
g. Parts I and III of the FAA History of Flight series (seepara- graph 6 below) should definitely be considered for thischapter in the event that your students did notsee them in AE-I.
h. The Theory of Aircraft Flight unit of instructioncan be quite a khallenge to many of your students, but it should also be one 'of the most funcotirsos/-As your grandmother used tS say, "Why does man want to fly anyway?He should stay home and watch TV like God intended."
1-7
I- FEBRUARY 1975
i. The'next time the class meets, I would suggestyou first dis- 7 cuss the,physical laws affecting aerodynamics. The Physics instructor may assist you here. Following a discussion of the basi94light concepts, you could have y ur project committees takeover and relate their findings the class. Afterward, be sure to summarize with, the class e key understandings that were derived from this chapter.
j. Answers to Chapter I Questions:
(1) Greeks (12) Rate of motion in a given direction
(2) Birds fly and man . does not (13) More energy is used up as the molecules accelerate, (3) Leonardo da Vinci thus reducing the pressure
(4)" Smoke (14), False - Aviators should under- stand-the principles of flight (5) 'Stability and Steering which contribute to safety and,efficiency
(6) John Montgomery; Otto . Lilienthal (15) Lift- the umard force exerted on a balloon or air- (7) '(b) being one.of the : . strip; Weight - die force t fiYst to build an inter- with which a body is attracted III/ nal combustion engine' to the earth;.Thrust- the, driving force exerted on any % (8) More control, more aircraft; Drag - a resistant
. power, higher speed forceexerted in a .direCtion opposite to the.direction (9) True of motion and parallerto the air stream
.(10) (answer :- page 8 of. . .. text) (16) True
(11)4,30 pounds '. (17) False
k. Student text assignment': read pages 1- 12. r-
6. INSTRUCTIONAL AIDS
a. Films (NOTE: Asterisks denote filM rating, e.g., *.** = excellent,, ** = TOT* = fair-or moll
(1) USAF
SFP 506 Air Power- Fools,Tiaredevils and Geniuses, 27'min., B&W, 1957 (This is a better aid for AE-I, but effective if not alreadyshown). ***
1-8 .. FEBRUARY 1975
SFP 1222 High Flight, 2 min., Col**, 1963. ***
TF-1-5300 Beyond the Stick and Rudder, 14 min.,145W, 1959. **
TF-1-4805 How an Airplane Flies, 26 min. B&W, 1953 (Uses old aircraft and not too interesting- preview before showing). *
(2) FAA
FA-905 Kites to Capsules, 5min., color, 1969. ***
'FAN-105 History of Flight Wright Brothers - Part I, 28 min.,,\B&W, 1971. ***
FAN 106 History of Flight-Wright Brother *. - Part II, 28 min., B&W, 1971. le**
b. Transparencies
V-1008A Forces Acting on an Aircraft in Flight
A 4030 Things at'Rest (Units activated after 1971-72 will not have 1030 and 1031)
V-1031 Things in Motion 'fr
c. Slides ---t V-0086 Slide 12 (NOTE: The narrative. ,40 ilides from series VA101 V -0087 Slide 4 may be appropriate for parts of this Chapter dependingon d. Miscellaneous your plan of approach)
(1) Demonstration Aids for Avi2tidh Education, compiled by CAP and reprinted by FAA, has some outstanding ideas for in- structional aids. The ideas will be useful thughout this' unit of instruction. This publication was dis ibuted to all AFJROTC units.
(2) Most school libra ies will have resource picture files that tan be used to h p you or your students prepare your bulle- tin board. It a4,o is advisable to alert your students to bring in materials in order to build a resource file. a. -1.1(NOTE: Some instructional aids will be listed for more than one chapter as they are appropriate as tqgport in several areas.)
1-9 FEBRUARY 1975
7.' PROJECTS:
a. See page 11.of the text.
bV1ther than just reporting on the (historical advancements of ight and their relations to the principles-of aerodynamics, A your students should be encoured to make mobiles.and mock-ups under the guidance of their arand industrial arts teachers. Be awe to coordinate with th se staff members early.enough to that they can integrate their planning and acquisitipn of materials with yours. Students should be encouraged to make materials for overhead and opaque projection when presenting their projects to the class.
c. Have each student report on at least one example of how Newton's Laws apply to students'in everyday.life.
d. Find out there are any members of the "Early Birds" or the "99s" in oiur area. They would be outstanding guest speakers.
e. Build a Forces of Flight demonstration model. Merely make a square wooden frame. Cut out a side view of an airplane, and suspend it with rubber bands inside the frame.
f The December 1913 issue of Flying magvine has Orville Wright's own account of the Wright Brothers' f{rst successfUl power-driven flight. Perhaps some of your students could locate this through the local library.
g. Build a model to demonstrate Bernoulli's Principle. (Also shown in the CAP booklet Visual ,Communications System by William J. Reynolds.) Using string, suspend two ping pong balls from a heavy wire. Using a straw, blow between the two balls and they will come together. By building a fr e s vice can be used on the overhead projector.
.I-lo 14 a FEBRUARY 1975
8. FURTHERRING:
a. See page:11 of the text. 4
b. Ae rospace Historian magazine.
c. Flying magazine.
d. Skylights. Published monthly by the national Aerospace Educa- tion Association, 1100 17th Street, NW, Suite 312, Washington DC 20036. Furnished to all- members of the organization as a part of th4'annual $10.00 membership fee. It includes articles on aviation and aerospacd developments and events.
e. Your Aerospace World,1974CAP (available through Bookstore, National Headquarters,' CAP, Maxwell Air Force Base, Alabama 36112).
. IDEAS FOR IMPROVEMENT OF THE TEXTBOOK AND/OR INSTRUCTOR'S GUIDE AND TEACHING TECHNIQUES MOST EFFECTIVE FOR THIS CHAPTER. TO BE COMI)ILED AT END OF TEXT AND SENT TO JRC
THEORY OF AIRCRAFT FLIGHT' FEBRUARY 1975
CHAPTER II-PROPERTIESOF THE ATMOSPHERE
This chapter approaches fligh from a different angle. Here, the student learns about the dium,Of flight- the atmosphere. The essential physical charact ristics of the atmosphere are sketched so thafthe student wi be able to understand sub-
sequent sections of this unit. -
1. OBJECTIVES:
a. Traditional - Each student should:
(1) Be familiar with the composition of the atmosphere.
:(2) Know at least four physical properties of the atmosphere.
b. Behavioral - Each student should, be able to:
(1) Describe the atmosphere.
(2) Identify tome of the features of the atmosphere's layers.
(3) Dtscuss at least four physical properties of the atmosphere. :A- 2. SUGGESTED OUTLINE:
a. The atmosphere:, what is it?
(1) Body of air which surrounds earth.
(a) Consists of different layers, shells -or spheres.
(2) Definition of air - Mixture of gases in the atmosphere.
(a) Nitrogen - 78.09%
(b) Oxygen - 20.93%
(c) 'Remainder- numerous substances in minute quantities includes argon, w*ter vapor, C0c,dust, smoke .etc. t a. b. Structure and composition of atmosp ere as it affects flight.
(1) Tropotphere.
(a) Lower )ayer, 5-10 miles tili ck.
0) The sun-warmed earth' as a source of heat.
(c) Most aircraft flight takes place in this tone from the surface to 26,000 feet at the poles and to 52,000 feet at the equator. 7F 142 FEBRUARY197
CO This zone contains over 80% ofour air (by weight). Molecules here cause more resistance to flying aircraft (drag) than in, any other zone. r\
(2) Tropopause - Narrow border zone between the op ,sphere and the stratosphere. The jet stream la globe circling wind with 100-300 miles per hour win. located at or near the tropopause.
(3) Stratosphere.
(a) Zone which'extends from the tropopause to about 264,000 feet above the earth's surface.
(b) Fairly constant frigid temperature in lower sections.
(c) Air is thinner in this regiOn, so ari airplane encounters less resistance from the air.
(4) Ionosphere - upper atmosphere.
(a) Contains few particles of air.
lb) Breakdown of gas particles because of electric discharges.
, . c. Physical properties of the atmosphere.
(1) Air is matter.
(2) Matter has weight and occupies space.
('3) ,Air occupies space.
(4) is a 'flutd.
'.(5) Ai is codpressible.
(6) 'Air exertspressure.
*, (7I Pressure force per Nnit:area*
(a) Force - measimed in'pounds.
Ali' pressure- measured in pounds' (of force) per, square inch (ofsurface area).
() -Experimentswith liqui mercury.
(i) Obser*Lthat air,prssure (showriby.rise and fallof mercury.in a,tube) changed as the'weather changed.
I :1 3
I8 FEBRUARY 1975
(9) Standard pressure - amount of atmospheric pressure necessary to raise a column of mercury to 29.92 inches.
(10) Absolute pressure - pressure measured by means ofa column of mercury.
(11) Relative pressure - reading relative to existing outside pressure.
, (12) Density -t mass per unit volume.
(a) Unit of mass- slug.
(b) Density decreases as height increases- the higher you go the less dense the air is.
(13) Air holds, varying amounts of water vapor. ( (a) Water vapor is water in a gaseous state. (b) Watef vapor weighs about five-eighths as muchas,a Simi ar amount of air.
(14) Increasing the temperature of air decreases its density if the pressure is constant.
(a) A given volume of hot air weighs less than the-same volume of cold air, r 3. ORIENTATION:
a. This chapter underlines the importance of the atmosphereas a primary factor'affecting the flight of aircraft. Much of the material is simply a review of rpterial covered in AE-I.
b. It is'important for the student to become acquOnted withthe composition and physical properties of the atmosphere in order to comprehend the problems encountered by aircraft, pilots,and passengers as they pass through the atnospere at various levels.
c. Knowledge of these properties will improve the student'schances of understanding how planes fly'when theyprogress to more complex subject matter dealing, with the theory of flight in subsecTent chapters.
4. SUGGESTED ,K,EY POINTS:-
I -a. 4n understanding of the atmosphere relative to its **V -9002, pp characteristics and elements of compositicin isan 40-41 important factor.in flight.' We learn that the body ** V-9005, pp ofair which surrounds the earth consists of different 1110 ,99 -100. layers or shells.
14,)_14 FEBRUARY 1975
b. Air is a mixture composed of several substances. ***V-9013, pp 8-12 Nitrogen accounts for 78.09% of air; oxygen for *V-9107, pp 1-3 20.93% and approximately 1% argon, hydrogen, **V-9156, pp 198-9 carbon dioxide, carbon-monoxide, and minute **V-9176, pp 12-13 quantities of rare gases such as helium, krypton *V-9013, p 4 and zenon make up the balance.
(1) Air at low altitudes also contains varying **V-9107, pp 1-3 amounts.of water vapor, smoke and dust particles **V-9187, p MET-2-3 c. The composition of the atmosphere varies in different **V-9013, pp 10-11, layers.The tropOsphere, which is the lower layer,. **V-9107, pp 1-3, is five to ten miles thick and Contains over 80% 221-222 of the air molecules. These molecules offer the **V-9181, pp greatest resistance to flying aircraft (drag). MET 1-7 d. Between the troposphere and the next layer, we have **V-9013, pp 10-11 a narrow border zone known as the tropopause. The **V-9107, po 1-3, jet stream', which is a high speed globe circling 221-224, 227 wind a eving speeds of from 100 'to, 450 mileSs an hour,* i at or near the tropopopause.
e. Above the tropopause we enter t e stratosphere which **V-9013, pp 11-15 extends approximately ten to 55 iles above the *V-9107p 1-3 earth's surface and has fairly c st4t frigid temperature in the lower sections. )4.
(1) The air is thinner in this region of the atmosphere and aircraft encounter less resistance from the air.
f. 'The upper atmospheric layer is known as the ionspher6 **V-9613, pp 12-13 .and contains 'very few particles of air. The few particles found in this region are ions (charged gas moletules). which give us electrical manifesta- I tions such as the Northern Lights.,
g. To date, of all the layers of tlie'atmosphere, the *1/-91107, pp troposphere is Most important because most aircraft. 221-222,_ fly withim this zone and most weather occurs here.
h. Air, a name conveniently. used for'atmosphere, ha. *V-9103; pp 19=11 several important physical, charact ristics: it *V-9107, pp 3-14., matter; it ..is e fluid, it is compr ible; it ex ,is ,*V-9156, pp pressure; ft-can hold varying amou s of water vapor;
212-'213 1 and it.is affected by changes in to perature. ***V-9176, p0 9-12, 61 -63 i, The weight of,air and.its density-varies. At nor sea level the4essure is approximately 15 pounds *V-9103, pp 9-11 per,sguare indh. As you climb upward in the atmosphere, **V-9156, pp 199- the air, becomes colder, thinner and lighter and at ,203 18,000 feet the pressure)conly half of that *"*Y-9176, pp 23-37 found at sea level.
48-53 - 1:15 ) k, FEBRUARYf1975.
(1) These variations in atmospheric.pressure affect ***V-9187, pp MET-7-10 pilots, passengers, engines, and the plane itself.
(2)Decreased pressure has a definitt effect on takeoffs and landings, rates of climb, air
speed, and,fuel consumption. -44
5. SUGGESTIONS FOR TEACHING:
a. Suggested time: 1-2-3 (Translationif you teach two academic periods per week,we recommend you devote one hour to this sub-
-, ject.. If you teach three periods per week you could devote two periods. If you teach four academic hours per week you could devote three periods to the subject.These'"Suggested, times" are just thatrecommendations.Adjust the emphasis' according to interest and talent--both yours and the students'.)
b. Much of this chapter is.a review of Aerospace Environment. You should know how extensively you have already covered this material and adjust the emphasis accordingly.
c. Science or Chemistry teachers may already have covered this material in their classes. As you discuss your instruction plans with them, they should be able to offer several additional ideas. Also, if you decide to conduct any of the numerous experiments available, you will undoubtedly want to borrow materials and supplies from the Science Department.
Demonstrations of the properties of air are very effective. In addition to the ideas listed in the resources for,this chapter you can (1) place partially inflated balloons- over the tops of.
two pop bottles, place one bottle in ice and the other in hot . water; (2) submerge an inflated balloon in water, (3) demonstrate different fluid densities dropping mercury into a beaker of water; (4) release two balloons one filled with helium and the other with air;-and,(5) place an uninflated balloon on one side of a balance scale and an. inflated balloon on the other.
e. AnsWers to Chapter II QuestionS-I
(1) Atmosphere (G) _True
(2) Troposphere, strato- .00) d. all of the above sphere, and ionosphere OR lower atmosphere, (11) Substances which may be made middle atmosphere, to change shape or to flow
and upper atmosphere . by applying pressure to thelli
S. (3) The mixture of gases (12) Pressure 'in the'atmosphere
1-16 S
FEBRUARY 1975
(4) Oxygen (13) Air pressing onthe mercury in the dish balanced the (5) troposphere or weight.of the mercury in lower atmosphere the tube. About.30"
(6) The ttopopause (14 False (you are measuring relative pressure) (7) 10 to 55 (15) Less (8) Ionosphere or upper atmosphere (16) Less; lighter
(17) Increa4es
f. Student text assignment: read pages 13 - 23.
6. INSTRUCTIONAL AIDS:
a. Films:
(1) .FAA: FA-603A Density Altitude, 29 min.cOler, 1966.-*** . I (2) See pages 18 - 19 of V-9175c and V1-91760%
b. Transparencies: 9'.
(1) V-1026 Air Slows Satellites .
(2) V-1034 Regions of theAtmos4ere
,(Units activated after 1971-72 will'not have these items)
c. Slides:
(1) FAA AP-1 "The Atmoiphere," 58 slides with a 23'min. sound- tape, 1965.
(2) ii-0087 Aircraft in Flight, slides,1 and2.
d. Miscellaneous:
(1) Demonstration Aids for Aviation Education', CAP, pp 2-8, 21/33.
(2) V-9176, pp 9-13, 23-37, 48-53, and 61-63.
(3) Most encyclopedias contain ideas for experiments to demonstrate the various properties of air.
7. PROJECTS:
a. See page 22 Of the text.
1-17
, FEBRUARY 1975
h. Have your students devise and perform additional experimentsto demonstrate the properties of air.
8. FURTHER READINGS:
a. See page 22 of the text.
'a b. Aircraft in Flight, CAP.
c. Most encyclopedias have excellent sectionson this subject. Many of them such as Compton's .and the World Book-also include excellent suggestions for experimentsand demonstrations.',
d. Your Aerospace World, 1974, CAP.' ".
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IDEAS FOR IMPROVEMENT OF THE TEXTBOOK AND/OR INSTR CTOR'S GUIDE AND TEACHING TECHNIQUES MOST EFFECTIVE FOR THIS CHAPTER. TO BE COILED AT END OF TEXT AND-SENT.TO JRC
THEORY Of AIRCRAFT FLIGHT
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CHAPTER'III - AIRFOILS AND FLIGHT
This chapter is perhaps the most critical section of theentire unit. Chapters one and two have introduced the student to the physical laws underlying flight and also to selected physical properties of the atmosphere. This chapter then relies on this physical'orientation to explain lift. An examination of the . airfoil precede's a discussion of the interaction df wind and wing. The Venturi tube's evolution into the airfoil concludes the discussion of the generationoflift.' The last section of the chapter discusses the ways in which liftcan be varied.
1. OBJECTIVES:
a. Traditional 4 Each student should:
(1) Know the basic elements of ap airfoil.
(2) Know the djfferenCe between pressure-differential and impact lift.
- , (3) Know how lift can be varied and what happens as a result.
(4) Understand ,he relationship o 1# to, the physical princi'ple's and properties of "the atmosph
b. BehavioraV Each student should be able to:
(1) Describe at least three of the basic elements,o *airfoil.
(2) State the differences betweenpressure differential,and impact lift.
(3) Discuss how lift*,can be varied and describe what happensas
. .(4) Relate lift to the physical principles and properties of iheiTmosphere.
2. SUGGESTED OUTLINE:
a. Definition of the term "airfoil"
b. Study of airfoil design
cl)- Use of the wind tunnel to study airfoil design
(2) Elements of an airfoil (leading edge, trailing edge, chord, and camber) 1 4 FEBRUARY 1975, T'
c. Relative wind and angle of attack $L-41t (1) Angle of Incidence
.(2) Attitude,
" d. Lift
(1) Bernoulli's Principle
(2) Newton's Third Law - imoact lift
(5) Total lift
-e, Varilbles affecting the amount of.lift generated
(1) .Angle of attack
(2) Speed of relative wind * (3) Air density
(4) Airfoil shape.
(5) Wing"area
16) Airfoilplanforms
(7) Devices,such as flaps; slots, and spoilers
3. ORIENTATION:
. . a. This phase is based on the physical laws developed in Chapters
One and Two. Newtonfr's Laws of Motion and Bernoulli's Law of ' Pressure Differential are the steps leading toan understanding of the airfoil's ability to move through the air andgenerate enough lift to suppor \the weight of the aircraft in flight.
Y (Lift variables, either from designor under pilot control, are discussed. These variables have magnitudeand can be calcblated mathematically. It is un to you to recognize the math ability levels of,your students and either go into problem solutions in depth,.or to stay at a lower ability level. You may want to challenge your better students by using contractsor some other individualized technique.
c. An understanding of thisthepter is important for the student because the next chapter deals with the other three forces acting" on an aircraft while in flight.:
I-20 I
4. 'FEB1UARY 1975 . y
4: SUGGESTED KEY POINTS:'
va. The term and concept of "airfoil" are important and *V-9065, pp 13-18must be understood. It is more than just the wing ***V-9118, (3rd ed.) of an aircraft. It includes any part of the aircraft pp 38-54 . thdt is designed to produce lift. **V-9156, pp 14-16 b. The wing is the primary airfoil that lifts the air- craft in flight. In the ign of airfoils, cross- sectional profiles are use Both curvature and thickness are necessary to ve an effective airfoil. To better understand these designs, it isimportant N that the student understand the parts ofan airfoil.
(1) The leading edge is the portion of tile airfoil that first meets or bites the air. Its actual shape is determined by the purposefor which the airfoil will be used. It may be blunt for slow moving aircraft or very sharp for high speed aircraft.
(2) lir.etrailing edge is that portion of the airfoil over which the air passes la*. It is the edge where the airflow over the upper surface joins the airflow over the lower surface. When these two streams of air rejoin, the upper stream resumes the same speed as the lower. The trailing edge will take on an added dimensionin Chapt& IV when the. supercritical wing is dis- cussed. 0 (3) The chord of the airfoils is a reference line from which the upper and lower contours ofan airfoil are measured: It is simply an imaginary straight line drawn through an airfoil from its leading edge to its trailing edge. This line is used as the reference line in measuringcamber or curvature of the airfoil.
(4) The camber of the airfoil is the amount of curvature of the upper or lower surface with respect to its chord. The curve of the upper surface is referred to as the upper camber, and the curve of the lower surface is referredto as the'lower camber. Usually the lower camber has less curvature than theupper camber, and it is this difference in curvature that leads to an increase in air speedover the upper sur- face of the airfoil, and a resultant decrease in'pressure (Bernoulli's Principle).
I-2-1
4 Nt \I ,
1
FEBRUARY 1975
c. The example of the student's hand out the car window' is used to explain relative wind. At ts point it is not important that the lift is prima ly impact lift. The important factor is relating is knowlidge to an airfoil moving thrciugh air. Th irstream flow- ing around the hand (airfoil) istermedthe relative t wind. It is not air in motion. It is he motion of ***V-9002, pp 55-6 Theaircraft through the air that produc s it. This t*V-9047, pp 76-79 wind always appears to come from a point directly **V-9089, pp 45-48 in front of the path of flight of the aircraft. There- ***V-9118, pp 39-44 fore, the direction of the relative wind is controlled **V-9156, pp 16-19 by the pilot, as he controls the attitude or position 24 of the aircraft. The attitude of the aircraft is its ***V-9157, p 69 position in relation to the horizon. The pilot can **V-9162, pp 5-6 change the angle at which the leading edge of the **V-9166' pp 2-7 airfoil attacks the wind. This angle between the **V-9167; pp 9-15 chord of the airfoil and the direction of the relative ***V-9187, pp AB -2- wind is termed the angle of attack. As the pilot t0 Ancreases the angle of attack, the lift also in- creases, as long as the flow of air continues to be streamlined. It is not necessarily important that the students understand attitude and angle of incidence, but it is very important that they under- stand thatthe aircraft can fly with a nose high attitude resulting in a large variance between relative wind direction and aircraft attitude or a very high angle of attack. Referring to the paragraph on page 30, it may help to point out that a climbing aircraft with a nose high attitude could'have a 0° angle of attack, but the same attitude would result in a very high angle of attack if descending. Of course the relative wind would be different for all three examples. c V
d. Remember that air is a fluid and that Bernoulli's **V-9002, pp 61-54 Principle applies in fluids; "As the velocity of a fluid increases, its pressure decreases." Since *V-9118, pp 32-33 the airfoil acts as part of a Venturi tube, the pressure above the airfoil is less than the-pressure ***V-9156, pp 11-15 below the,airfoil; and as a result, the airfoil is lifted or raised. The camber of the upper part of **V-9162, pp 4 -5 the airfoil causes the air passing over this part to travel at a greater, speed than the air flowing past the.much smaller camber of the lower part of the airfoil., The greater speed of the upper airstream results in the lower pressure above the airfoil and its resultantift. This particular lift fOrce is duel-to a difference in pressure and is termed a pressure differential lift.This lift acts in a direction opposite to gravity and perpendicular to
I -22 . 4--,k ,,....., FEBRUARY 1975
the direction of the relative wind. As this lift is being developed by the movement of the aircraft through the air, some of the airstream strikes against the underside of the wing. This air is deflected downward, and according to Newton's third law'that to every force there is an equal and opposite, reaction, the resistance or inertia of this air exerts a lifting force. This impact lift varies Ith speed and angle of attack. Normally it is u h less than pressure differential lift. Thetwptypes of lift combine to produce total lift.
e. The pi ot must be able to control the two types of lift a ting on.the aircraft. As mentioned earlier, the pilot controls angle'of attack. As he changes this Ogle, he changes the amount of lift ofthe ***V-9002, pp 55-58aircraft. Mathematically all the lift forcescan be added together and the sum of these forces istermed **V-9118, pp 38-42 the resultant. This resultant has magnitude (size), direction and location. The point where the re- sultant intersects the chord of the wing is termed **V-9156, pp 20-22 the center of pressure (C/P). As the angle of attack increases, this center ofpressure is moved forward and the lift increases until theburble point, is reached. The-burble point is the angle of attack where the streamlined flow of air beginsto break down and become turbulent (burble).As the burbling increases, the amount of lift generated is no longer sufficient to keep the aircraftairborne. This point is termed the stalling point, andthe air-
craft begins to descend. ;-
f. Other key factors that affect the liftgenerated by an aircraft:
(1) The actual lift is directly proportionalto the density of the surrounding air. It is ***0-9018, p 43 proportional to the speed of theaircraft as well as the area of the wing.The denser the t air, the greater the lift, all otherfactors being equal.
The aircraft outline viewed from directlyabove or below is called a planform.
The planform of the wing allowsus to measure the aspect ratio. This is the span of the wing V-9018, pp 41, divided by the average chord of the wing (or 54, 56-57 the wing span squared divided by total wing area). Usually, the higher the aspect ratio, the more efficient the design of the wing. 4
1-23 t,C1 FEBRUARY 1975
(4) Flaps are devices for chanOng the camber of ***V-9002, pp 65-67 the wing,. This can be done while in flight.,. ***V-9089, pp 50-51 ***V-9118, pp 63-64, 74 *Vr9T67, pp 24-27 (5) Slots are moveable or fixed sections of the leading edge of the airfoil. They also change **V-9002, pp 67-68 camber and are used to smooth the airflow at, **V-9118, pp 65-66 high angles of attack.
(6) Spoilers are small surfaces either recessed into theuppersurface of the airfoil or pennahently fixed in a certain position.When raised, they "spoil" the airflow,and lift is'' reduced. They may be rather large at the trail- ing edge and when raised serve as "air brake)"
5. SUGGESTIONS FOR TEACHING:
a. Suggested time: 3-4-5
b. In general, students should be inter sted inLatand how an aircraft can fly. One methpd to con ider is the lecture dis- cussion methswhereby, students with some knowledge of aircraft flight can bencouraged tolist kno n facts on the chalkboar 'r One introduc ory question could be,'whydoes an aircraft fly Another, to lead into a study of the airfoil, is "what isthe most critical part of the aircraft?"
c. Students could be asked4o constructaper airplanes, then fl them so that design differences'can be analyzed. Model airplanes, paper airplanes, box kites, regular kites`- all can be used by
the instructor and students to demonstrate the key concept of . what an airfoil is and what parts it contains.
d. Panels could be set up by the instructor using ithe above models, to help illustrate the factors affecting lift.
e. Student oral reports could be presented on such key ite_sas:
(1) Use f the wind tunnel'
(2) Shapes of airfoils
(3) Importance of the angle of attack
(4) Burble point and stalling point
(5) Flaps, slots, and spoilers
f. Depending upon the ability and needs of the students,you may. want to construct some math problems concerning changes in some of the lift variables. The solving'of these problems would give.
1-24 FEBRUARY 1975
the students a practical working kpowledoje of thesefactors, The physics instructormay be able to help you construct these problems. Aspect ratio problemscan be devised easily by substituting different numbers in the formulason page 38. g. Refer to Figures 16 - TT on page.34 of the text. Your sharper students may question the statements concerning climbing with- . out a change in the relativewind. These pictures were drawn showing the flight` conditionsat the instant the situation happened. Obviously the relative windwould change toone. from a more upward potition in Figures 17 and 18. The condition in Figure 19, if allowed to persist would resultina rapid descent.' You can testyour students' knowledge of relativt' wind by asking them what would happen to relative wind ineach 1 instance. 9 While there are many excellent audiovisual materialsavailable to support this Chapter,you can supplement them by making additional transparenciesor models. Plans for a wind tunnel which can be usedon an overhead piojector can be fouridvon page 17 of William J. Reyhold's4CS,Visual Communications Systems published by arandreprtnted by FAA. If you are unable to .get dryrice,'fasten long threadsto the inlet end r of the wind tunnel. Thecthreads will alsodemonstrate air flow visually on the overhead.'There may be shop students looking for lust sucha project. i. The first 30 frames Of theTheory of Aircraft Flight,Workbook ,(V-7201W) will .serve as an_excellentinstructiOnal.afdand as an introduction to Chapter IV. j. Textbook, correction: "is" on page 29 shouldnot be'6oldfaCed. k.' Answers to:ChapterIII questions:
(1) airfoil True
(2) False (d) all of, the above
43) True lift
(4) leading edge, trailing (18) magnitude, direction, and edge, chord, and camber location
(5) more (19) the point of intersectionof
the'resyltantand the wing, (6), trailing edge chord
(7) chord . (20) (d) of the above
(8) the characteristic (21), forward curve of an airfoil's upper or lower surface
1-25 FEBRUA.0\1975 2
(9), relative wind (22) it decreases'
(10),. False (24) stalling,pointi
, . (1'1) (d) attitude ' (24) di fectly. , .
(12) the,force which acts (25) greater perpendicular to the relative wind in 611 ". (26) greater upward direction or the opposite of Weight, (27),planform
(13) impact (:28) statement of the relation- ,ship between the length and (14) total lift width'of a ng . V
(29) 'False
(so)' a. 2 b. 3 c. l'
I. 1.' Student tcixt assignment:read,p'ages 25
6. INSTRUCTIONAL AIDS' .42
a. Films:
(1) USAF \ IF -1 -0160 Aerodynamics- Air Flow, 18;in.', B&WI 194ir **
TF-1-0161 AerodYriamics 4 Forces Acting,on an Airfoili 26 min., B&W, 1041.
TF-14804 How an Airplane Flies, .26,mift.',.8&W, 1053 (tee note in Chapter I of this handbook). *
TF-1-5300 Beyond the Stick and Rudder, 14,min., B&W, 1950. **
TF-5521 Flying the:SweptWing, 24 min., 66104,1963. * *
(2) FAA
FA-70i How Airplanes Fly, 18.min., color., 1969;.*** (might Be bettor saved until Chapter IV or used-,as aitransition)
b. Transparencies,
V-1001 Airplane Components ')
I-26-
X. IP
FEBRUARY. 1975
e
V-1003 Wing Structure g
y-i.005A Lift ,
V-1006B Airflow Across Wings
V-1063 Parts of an Airfoil
V-1065 ForOes of Flight (Lift)
F. c. Slides
V-0087Aircraft in Flight- slides 3theoUgh.7 and R through 11 .-
d. Film Strips
. 'Film strip No. 1, "Lift and. Thrust" JAM'Handy film- strip series'Aircraft -Their Power and Control.These can be purchased individually ($15.00 each)or'as a set, with cassettes (#..1H5960FC, $90.00) or records (0JH5960 $84.00) fromScott Education Division, 104 Westfield Ro Holyoke, MA 01040. Ohey are highlfrecomended andsho d be pur- chased through your-school library)'. e e. Miscellaneous
(1) Demonstration Aids For AvtationEducation, pp 11-13.
(2) Activity cards 1, 2, 3, and 6"whichare furnished with the JAM HANDY materials cited in 6:d.above.
(3) Battery Powered CesSni 150 Flying Model- available from: Cessna Aircraft Company, Air Age EducationDepartment, P. 0.' Box 1521; Wtchita, Kansas 67201.
(4), VFR Exam-O-Grams, 17;27; and 47. A free set of Exam -0- Grams may be obtained from: FAA AeronauticalCenter, Flight Standards Technical DivisionOperations Branch, P. 0: Box 25082, Oklahoma City, Oklahoma73125.
7. PROJECTS:
a. See pages 41- 42 of the'text.-
b. Use the'rever'se cycle.On a vacuum'cleanerand a ping pong ball to demonstrate lift., Once the pingpong ball is suspended, .yol'i should be able to put theair stream at an angle and the lift will keep the bell aloft atan angle. l
' I . ,ti 1-27
t. FEBRUARY 1075
c.. Demonstrate lift by placingje spool on top,of a piece of paper and inserting a pin up through the paper into the spool hole. As you blow through the spool, lift will keep the paper on the bottom. Challenge some of your strongest boys to blow the paper off.
8. FURTHER READING:
a. See page 42,of the text.
b. V-9198
C. Aircraft In Flight, CAP
d. Aviation Week and Space Technology
e. Flying. magazine
. f.' The TUSC News published by 'technology Use Studies Center, Southeastern State College, Durant, Oklahoma 74701 (all ApROTC units are'on their mailing list).
g. Your Aerospace World, 1974, CAP.
1-28 . 34 4 4. 1
410 IDEAS FOR IMPROVEMENT OF THE TEXTBOOK AND/OR INSTRUCTOR'S VIDE t AND TEACHING TECHNIQUES MOST EFFECTIVE FOR THIS CHAPTER. TQ BE COMPILED AT END OF TEXT AND SENT TO tIRC . . , THEORY OF AIRCRAFT FLIGHT . .
.
.44
4.
I
f 13 FEBRUARY 1975
CHAPTER IV - EIGHT, THRUST, ANDDRAG
This chapter explains the other threeforces acting on an aircraft in straight, level, andunaccelerated f ight: 'After the student understands all 'theforces a ting on an aircraft in straight, level, andunaccelerate flight, he can then move on to`examine the three-dimensionalaspect of aircraft flight. ,
1. OBJECTIVES:.
a: Traditional Each student should:
(1) Know-how the "balance of forces"keeps an aircraft in ;EFF-air.
(2) Know how Newton's Third Lawaccounts for thrust.
3) Know the difference between induceddrag and parasite drag.
(4)' Know how designersreduce turbulent flow drag..
(5) Know the definition of supercriticalwing.
(6) Know how the four forces relate'tohelicopter flight.
b. Behavioral- Each student should be able to:
(1) Discuss how the "balance of forces"keys an ,aircraft in. the air.
(2) Describe how Newton's Third Lawaccounts for thrust.
(3) 'Differentiate between induced dragand parasite drag.
(4) Outline how designers reduceturbulent flow, drag.
,(5) Define supercritical wing.
(6) Show how the four forces relateto 'helicopter flight.
2. SUGGESTED OUTLINE:
a. Four forces maintainan aircraft in straight and level un- accelerated flight.. Theeforces are lift,* weight, thrust, and drag. Lift was.covered in detail 3nthe last chapter.
b. Weight opposes, the forceof lift FEBRUARY 1975
(1) The total weight of the aircraft is caused by the pull Of gravity
(2) 'The relationship of the center of gravity to weight and aircraft flight
.c. Thrust,drives the aircraft forward
(1)' Reciprocating engines
,(2) Jet engines 4
d. Drag opines the thrust of the aircraft
(1) Induced drag
(a) Affects lif ing surfaces,
(b) Vortices
(2) Parasite drag
(a) Skin friction drag and boundary layer air
(b) Turbulent flow rag
(c) Streamlining to 'vercome drag
e. Supercritical wing
(1) Boundary layer air again
(2) Shock waves
,f. Helicopters - affected by the safe four forces
(1) Hovering
(2) Forward, sideward, or rearward ,flioht all work the same
3. ORIENTATION:
. This chapter covers the other three for es acting upon an aircraft in straight, level, and unaccel rated flight. The
last chapter dealt with the forces of lif . This chapter will deal with weight,,thrust; and drag. The s percritical wing ( is introduced in this chapter because the p oblems encountered are primarily re ated to drag. The helicopter is covered last because in this y it both *covers an important area and serves as an excellent review of the forces of flight.
I -30 3 7 FEBRUARY 1975-
b. Once the student has a clear understandingof these four forces in artnchanging_situation, he will be preparedto ee,in his -stud of the aircraft in motion ina three-dimensidnal sea of air.
4. SUGGESTED KEY POINTS.
a. The pull of the earthon-the aircraft isresponsible for the total weight of the aircraft.This pull of **V-9002, p 39 gravity is a force which act in a direction *V-9005, pp 18-19 opposite to the vertical component of lift.The *V-9065, p 22 further the aircraftmass is from the'center of **V-9118, p 44 the earth, the less the pulling force ofthe "V-9156, p 27 earth on it. In other words, it weighs less. The force of weight acts verticallydownward from the center of gravity (CG) of theairplane.
b. Thrust fs the force on an aircraft whichgives it forward motion. It is related to Newton's Third *V-9005, p 19 Law of Motion. "For every action there isan **V-9065, p 46 equal and opposite reaction." **V-9118, p 45 *V-9090, p 9 (1) Both jet and reciprocating enginesoperate ***V-9162, p 7 as reaction engines.
(a) The reciprocating engine transmits the energy from the burning fuel through a complex system to the propeller. The turning of the propeller pushesa mass of air to the rear, and the reaction to this push (Newton's Third. Law of Motion) moves the aircraft forward.
(b) The jet engine transmits theenergy from the burning fuel directly out the exhaust system. The reaction to this force is against the walls of the combustion chamber, and it moves the aircraft forward.
c. Drag is the force which opposes the forwardmotion **V-9002, 6 of the airplane. The Vital drag of the aircraft 59-65 opposes its thrugt. This total, drag can be *V-9005, p.19 divided into two major types: *V-9013, pp 46-57 / (1) Induced drag is that part of the totalair *-4-9065, pp 20-22 resistance caused by the lifting surfaces. *V-9118, pp 34-35, It is an unavoidable result of lift, caused 37-38 . by the change in direction of the airflow ***V-9187, pp AB-6-12 ';'Aresulting in the formation of trailing **V-9156, pp 28-29 vortices from the wings. One of the ways "V-9162, pp 96'97 the designer works to reduce this drag is "4-9187, pp WT-1-9 by increasing the aspect ratio'of the wing.
1-3,1 s8 FtBRUAO 1975
Th 'pilot can control' the magnitude'of this dr g by changing Ms angle of attack
(2) Pa asite dra is that part of the/total air resistance caused by all the non-lifting 1 surfaces of the aircraft. The movement of it ever the skin surface of the fuselage, and othe fixed obstructions resilts in a friction loss termed skin friction dra Closely elated to this s in ict on rag **V79156, pp 9-31 is the very thin layer of aU moving next to the surface of the airfoi This, very .***V;9162, p 10 thin layer of air becomes more turbu)ent as it passes from the leading edge o 'the airfoil, to the trailing edge of the airfoil.` It is termed boundary layer air. Also related to this is *mrbulent flow drag Which is caused by anything interfering with the streamlined flow of air about the aircraft. Aeronautical engineers normally use the.teardrop shape as often as possible in their designs'. By
doing this, air turbulence and the resultant ,
. drag is reduced.
d. As high speed aircraft flew in the transonic and supersohic areas, the early separation of the boundary layer led to large shock waves and a **V-9118, pp loss of efficiency due to the reduced lift.The 45-47, 68 supercritical wing is merely one of many attempts to overcome this problem. At high speeds, the **V-9156, pp unique shape causes the boundary layer separation 496-503 point to move farther back on the wind and reduce the shock wave size. Strangely enough, at transonic speeds, the boundary layer will ,adhere to the sur- face longer if it is slightly more turbulent.
e. Helicopter flight is really simpler than aircraft flitt th4 students will accept the fact that *V-9002, pp 390-6the thrust of the propellor(s) has both horizontal ***V-9013, pp 656- and vertical cdmponenfs. 662, 668, 672-677 (1) Hovering means 'that both thrust and lift are *4*V-9118, pp-94-104 in a vertical plane and exactly equal (4th ed.) to the sum of drag and weight. ***V-9135, pp 7-10, 16-17, 19-27 (2) Climbing or descending_ straight up and down
***V-9156, pp 166-172, merely pearls that lift plus thrust is greater 179-184 or less than drag plus weight respectively. **V-9168, Plane 10 (3) Flight in any direction, forward, sideward, or rearward, is identical insofar as the four forces of flight apply. The resultant of lift and thrust, accomplished by tilting III/ 1-32
rick c.3
e FEBRUARY ,1975 .
the rotor, must be greater than the resultant o1 drag and weight. For example, if the horizontal component of lift exceeds drag and the vertical component of lift equals weight, the helitopter will travel intthe horizontal direction of thrust at a constant
- altitude. I
5. UGGEST ONS FOR TEACHING
a,' Suggested time: 2- 4
b. ,Introducea study o weigh by asking uch questions as, "How did Newton explain the app e falling toi the ground?" "How high up must we go to expe ience.weightlessness?" The students tan bring in discussion points learned from their science classes. Simple demonttrotions can be performed by students or the instructor to develop the key points into student dis- cussiona. One such demonstration is to release a balloon ill
class to illustrate thrust. , -
c. As students begin to understand the four forces.interacting on an aircraft'in straight and level flight, problems can be presented to students for solutions.. Students can be asked to predict what happens to the 'four *forces in flight when the angle of attack is changed.
.d. Oral reports by students can be Asigned on such key items as:
- , (1) Newton's Third Law of Motion
(2) Reaction engines
(3) Induced drag and the aspect ratio
(4) Skin friction drag and boundari, layer air
(5) Turbulent flow drag and streamlining
e. The supercritical wing will probably be too advanced for most of your students in which case you will want to either skip it or mention ft as a new airfoil design. Several 'new designs- are presently being studied such as the anti- symmetrical wing, the oblique wing, the "free wing" and the "flying wing." (See references bdlow). A Piper PA 34 Seneca modified with a supercritical wing has alreadj, flown. Fuel economy improved up to 10% (TUSC News, December 1974). All of these areas are 'excellent possibilities for student research and reports:
f. Your students can also be assigned research reports depending on their ability. Your better students could find out what
1-33 .7 FEBRUARY 1975
the ReynoldA Number is (see V-9118) and how it applies to drag. Others could report on laminar flow.
g. The last subject in Chapter IV on helicopteis serves both as an excellent means of testing your students' grasp of the four farces of flight and as an introduction to vectors and resultants, which will be necessary for an understanding of the material in Chapter V.' A good review would be to draw a direction of flAght for a helicopter and have your students .draw the'appropriate vector., for weight, drag, thrust, and lift that would be required for that direction of flight.
h.. It is possible that your students will be Intrigued with, helicopter flight. Be prepared to answer.such questions as "How ftes the pilot change directions?" and "What happens when the engine quits?"for this last question, the simple 0 autogyro mentioned on page 55 of the text will be helpful . (see plans below).
i. Answers to Chapter IV Questions: 7.
(1) Gravity (9) By decreasing the angle of attack (2) (b) center of gravity All drag components except
( ) force which drive's induced drag the aircraft forward Skin friction drag and (4) Recipracittng and turbulent flow drag
jet engines , ,(12) Boundary layer air (5) The force which ter* to. retard an aircraft's (13) More
. ,progreskthrQugh the air or ttirfoi.ce which (14) Keen the aircraft clean and opposes thrust well polished; removing surface irreoularities ,(6) The change in direction of the airflow (15) Streamlining
'47) Retardk,,,absorbing .(46) The teardrops
(8) By reducing the area (17)-Supercritical wing of the wing affected .5; by-wing tip vortices ..(18) Impact
. (19) True
(20) By changing the tilt of the I . rotor._ , .
Student text assignment: read pages 45 56.
I-34 la s.
FEBRUARY 1475
6. INSTRUCTIONAL AIDS:
a. Films:
(1) USAF
TF-1-4804 How an Airplane Flies, 26 min., B&W, 1953 .*
TF-1-4805How an Airplane Flies, 34 thin., B&W, 1953 (probably more appropriate for Chapter V). .*
a TF-1-5300 Beyond the Stick and Rudder, 14 min., B&W, 1959. ***
TF-1-5340 High Speed Flight - Approaching the Speed of Sound, 27 mirC.,. color, 1959. ***
TF-1-5341 High Speed Flight'- Tran?onicTlight, 20 min., color, 1959. ***
TF -5521 Flying the Swept Wing, 24 min., color, 1963. **
TF-5550 High Speed Flight -.Beydnd the Speed of Sound, 20 min., color, 1962. *
III/ TF-6018 Helicopter Performance Data - Temeraihure Makes the Difference, 26 min., color, 1967. *
(2). FM
FA-10-70 Caution: Wake Turbulence, 16 min., color, 1970. ***
FA-703 How Airplanes Fly, 18 mln., color, 1969. ***
(3) Shell Film Library (borrower pays return postage - 450'North Meridian Street book at least 4 weeks in Indianapolis, Indiana 46204 advance)
ApProaching the Speed of Sound, 27 1/2 min., color, 1958. ***
Beyond the:Speed of Sound, 19 min., color. .***
Transonic Flight, 20 min., color, 1959. ***
, b. Transparency
V -1008A Forces Acting on an Aircraft in Flight
c. Slides
. V-0087 Aircraft in Flight - slides 8, 9, 11-13, 21-25:'
1-35 FEBRUARY 1975
d. Film Strips
Filmstrip 1, "Lift and Thrust" and Filmstrip 3, "How Helicopters Fly" from the JAM HANDY series "Aircraft; Their Power and Control" (see Chapter III this handbook).
e. Miscellaneous:
(1) Autogyro. To construct it you need a rectangular sheet of paper (5" X 8" works well) and a paper clip. Cut (or tear) on the solid lines and fold on the dotted lines as shown below.
When You lift it up and let it go it should autorota'te.
(2) Either the chalkboard or the overhead projector may be used effectively to explain the forces of flight. How- ever, if you want something more permanent or professional,' a flannelboard or a magnetic board are both very effective.
(3) Use the fo ces of flight model described in Chapter
7: PROJECTS:
a. See page 55 of the text.
b. Have your students conduct experiments that help expl1 in weight,
thrust, and drag. They should demonstrate them or report the ' results.to the class. / t 1-36
43 '
FEBRUARY 1975
c. Have your students find examples of how streamliningis used in everyday life, e.g.;'autos, boats, motorcycles,etc., and discuss the effect on operating efficiency.
VSTOL aircraft are not discussed in this text.Ask your students toreport on the latest VSTOL developments and explain how the forces of flight abply.
. FURTHER READING:
a. See page 55, of the text.
b. Aircraft in Flight, CAP.,
c. Aeronautics, Space in the Seventies, NASA, 1971 (EP-85).
d. Ae ace magazinerpublished monthly by Aerospace Industries' SSOC1a ioni(September 1973, pp 8-13; September 1974, pp 11-16).
Airman's Information Manual, Part I, FAA (Ststionon Wake,
Turbulence).
As, Aviation Week and Space Technolog' (e.g., Mar'ch22, 1971, p 48; August 20, 1973, p 56; and November 25, 1974,pp 43-45).
o ular Mechanics magazine.(.March 1973).
h. Science Direst magazine (February'1974)..
i. The TUSC News.
j. V-9110 -(Helicopters and Autogyros).
k. Your Aerospace World, 1974, CAP. *,
I
1 IDEAS FOR IMPROVEMENT OF THE TEXTBD6VAND/OR INSTRUCTOR'S GUIDE . AND' TEACHING TECHNIQUESMOST EFFECTIVE FOR THISCHAPTER. TO BE COMPILEDAT END OF TEXTAND SENT TO JRC
THEQAY OF AIRCRAFT FLIGHT
yr
74
.1%
1
. ,I FEBRUARY 1975
CHAPTER V - AIRCRAFT TION AND CONTROL
This chapter examines the aicraft in motion. Stability, climbing flight, am' turning .fight form a convenient framework for discussinc the -chanics of aircraft in motion.
JECTIVES:
a. Traditional- Each student shduld:
(1) Know the three axes of rotationused to- describe the movement of aircraft.
(2) Know the resulting motion aboutthese axes when an . WEraft rotates in variousplanes. f (3) Know the effects of lack ofstability on the axes of rotation of the aircraft.
(4) Know the concept of-aircraftcontrol and know at least. TEFie control surfaceS.
(5) Know which ccintrol,surfacesaffect which aircraft motions.
(6) Understandrate of climb and angle ofclimb.
b. BehaVioral- Each student should be able to:
(1) List the three axes ofrotation.
(2) Describe the resulting motion about these axes whenan a rcraft rotates in various planes!
(3) Discuss the effects ofa lack of stability for each of Tfiii3gOofan aircraft.
(4) Outline the concept ortircraft'controland list at three control surfaces,'
(5) State which ntrol surfaces affectwhich aircraft motions:
(6) Explain rate of climb andIt le of climb.
2. SUGGESTED OUTLINE:
a. Aircraft fly in three dimensions
b. Axes of rotation- types of aircraft motion
(1) Longitudinal axis- roll FEBRUARY 1975
2)* Lateral -pitch
(3)- Vertical axis- yaw
c. Aircraft stability-central concept behind "aircraftdesign? - operation, and control
("F) Statib stability le* (2) /eutral stability
0)", Positive stability
(4) Negative. stability
... (5) Dynami stability
d Longitudinal axis stability- factors involved
(1) Intentional)y noseheavy balance- location of Center of Pressure compared to Center of Gravity
(2) Effect of wind movement over the airfoils ti 4 (a) Downwash
(b). Slipstream
e. Lateral axis`stability factors involved
(1) Dihedral
(2) Keel. effect
(3) Sweepback
f. Directional Stability*.
g. Aircraft control- hbw maintained
(1) Controls- - actual devices regttldting speed,directioA, altitude, and power
(2) Control surfaces
(a) Ailerons - roll
(b). Rudders.- yaw
(c) Elevators - pitch
(d) Trim tabs - fine tuning FEBIttlfitY 1975
4 (3) Climbing flight
(a) Reserve horsepower.-
(b) Power loading 1
(c) ClimlAng- angle and rateof climb
(d) Service 4eiling and absolute ceiling .
(4) Aircraft turns- factors involved
(a) Effectiye lift
(b)* Centrifugal .force .
(c) Angle of bank ,
(d) Skid c?a
e) Slip
1 (f) Effects of controllirfaces inturns
h. Aircraft motion and control- effects of throttle and control surfaces
3. ORIENTATION:
a. The study of aircraft motion andcontrol is baied4upon the backbroulid developed:in ChaptersIII and IV.' Aircraftare able to sustain flightyhenthere is a. balanceamong the" forces of lift, weight, thrust,and drag. When one of the forces is too far out of balance,some control adjustment must be made or it will beimpossible to maintain safe flight fo r very long.
* . b. This chapter looks at ,theaircraft once it is in flight. It 'deals with he axes of'rotationa d the movement the aircraft makes around these axes. It expl ins the concept ofstability in flight. The chapter includes ircraft controls and the role they play in movement of the Oa
4. SUGGESTED KEY POINTS:
a. There are three types ofmotion other than *V-9002, pp 83-84 straight and level flight.:Aircraft can move "**V-9187, pp und%three axes of rotation:'longitudinal A8-13-14- (rol-1)'; lateral (pitch);and vertical (yaw).
1-40 (, 48 a, X.1 , .
FEBRUARY 1975
b. Stability, an extremely important concept in aircraft design, is divided into two types: ***V-9002 pt) 88-92 static - the aircraft's tendency to return to *** pp 20-21 its original poition and dynamic -'the tendency 62- to return to its original position with a minimum **V-9013, pp 62-65of restorativie Oscillations. ***V4156, pp 109-I13 **V- -9167, pp 65-70 (1) Longitudinal stability infers that an aircraft will not pitch unless some external -force raises or lowers the nose of the aircraft. It is necessary to, have a slightly noseheavy balance in order to have good longitudinal stability. Therefore, aircraft are con- structed 'so that the Center of Gravity will be ahead of the Center of Pressure. This tendency to be note heavy is overcome by downwash, a downward movement of wind on the tail of the aircraft.
(2) Latei-al stability infers that the wing tips "V-9156, pp 113-116 of an aircraft will hold their positions (the aircraft will not roll) unless acted upon by some external forces. Factors involved which maintain this stability are dihedral, keel effect, and sweepback.
(3) Directional stability is the tendency not to yaw. It is determined by aircraft-con-
***y-9156, pp 116120. struction. The chief factor contributing . to directional stability is the vertical fin and side area of fuselage behind the Center of Gravity.
c: Controls refer to devices by which the pilot "V-9002, pp regulates his aircraft. oThese include ailerons, 92-97 rudders, and elevators, all of which are moveable ***V-9005, pp 2144, airfoils. Using these the pilot can change the 67 .attitude of the aircraft. Additionally, secondary "V-9118, pp7J-74 control surfaces called trim tabs may be attached ***V-9122, pp to these. Certain lift devices such as flaps, 308-318 slots, and spoilers were discussed previously ***V-9161, pp in the chapter on lift. These are sometimes ton-
2-1-5 I sidered when discussing controls. ***V-9187, pp - 14 -17 (1) Climbing flight is dependent upon reserved, ***V-9002, pp0-72 horsepower in the aircraft engine. Factors involved include rate of climb and angle of climb. Service ceiling, the altitude at which the maximum rate of climb is 100 feet per minute, and absolute ceiling, the altitude at which the aircraft ceases to climb, are both important factors involved in climbing. 49 FEBRUARY 1975
(2) Forces in turning involve the principle of .***V -9002,pp 46, 70-72 centrifugal force. Turning factors such as ***V -9005,pp471-73 angle of bank, skids, and slips Can be more **V -9090,p 33 easily understood when you visualize lift ***V-9161, in vertical and horizontal components. ***V -9162,pp q-48 d. Aircraft motion is controlled by the throttle and **V-9002,p 92 the control surfaces. Through use of these controls, **V-9047,pp 79-82 the pilot changes the balance between the four ***V-9156,pp forces: thrust, lift, drag and weight. 120-123 (1) Throttle is the up and down control
(2) Elevators control speed
. (3) Ailerons and elevators turn the aircraft
. 4 (4) Rudder corrects for adverse yaw.
5. SUGGESTIONS FOR TEACHING:
a. Suggested time: 4-5-5
b. Student, text assignment: read pages 57 = 83.
c. The best'suggested teaching method for this chapter would be a combination lecture, demonstration, and guided discussion. The theory of aircraft motion,and control can best be demon- strated by use of 'a model airplane with moveable controls. The axes of rotation can be shown by inserting sodastraws or some other device throughsthediongitudinal,'vertica) and lateral axeslof another simpler model with holes drilled through it. Discussion and demonstration of roll, pitch, and yaw could be' developed along 'these lines, The instructor should use a hand-held moddl, moved in changing erections in his lecture on aircraft,stability.VarioUs*MOVemerts,mid..., changes of direction could very well demonstrate these points. Perhaps you could havesome shop students make several small simple models so that students would havea better chance to handle the, model.
d. SoMe of the key points in this chapterare very difficult for students to grasp. You may have to use several different eX- planations in order to clear up confusion. Some possibilities are:
(1) L ngitudinal axis stability is hard to visualize. Be ure to point out that the horizontal stabilizer is fastened on slanting dowmtoward the frontso that its' angle of attack is negative., Naturally, they should
I-42 50 I
' FEBRUARY 1975,
come to understand that this whole setup is designedto achieve both static and dynamic stability.
/ (2) Stability may be compared to the ba lance of forces,i.e., a balance of the four forces of flight would bea static stable condition. Applying thrust would create'an unstable condition, but drag and possiblya loss of lift would tend to bring the aircraft back to equilibrium- static stability.,
(3) Some students will undoubtedly become confusedwhen dis- cussing movement about an axis, 'e.g., pitch aboutthe lateral axis, only to find out that a resistance to pitch is stability along the longitudinalaxis. Without a model, it will be impossible to make itcompletelyclear for all students, however, you might equate their automobileto directions) stability andyaw. If the front wheels% are out of alignment, the -steeringmay have negative stability along the longitudinal axis and about the verticalaxis.- directional instability. Stability refers to motion about one axis While moving the entire lengthof another axis. Longitudinal stability- if the nose gilds down, the longitudinal axis is moved around thelateral axis; '- Lateral stability- if a wing comes up the lateral axis is moved 'around the longitudinal axis; directional stability - sideways movement of thenose along the longitudinal axis (the direction you're headed).about the vertical axis'.
(4) Forces in turns, slips, 'and\Skidscan bd confusing. The most effective system I'veseen is to divide lift into vertical and horizontal components with entrtfugal force and weight counteracting them. Any ve for or resultant out of balance with its' oppositeco terpart will lead to a climb, descent, skid,or slip. A good quick way to test your students' comprehensionisto have them complete the missing vector/resultants inFigure 43, assuming it's a coordinated turn.
k (5) Some 'of yOu fighter types will surdly takeissue wth'the statement that the throttle controls altitudeehiLthe elevators airspeed. Before you enlighten your stnbents with "the way it really is," remember that'sthe way it's taught in FAA flight training and that'sthe way it will be taught to them when they startto fly.
. e. Some of your students may have gasoline-poweredflying models. Have them put on a demonstration explainingthe controls. Maybe they will let other students fly them. f. Regarding question 6, page 81 of the text. The B-58 is a good example. Because the line of thrust on an outboard enginewas
1-43 5'! , FEBRUARY 1975
so far from the CG, if one suddenly failed at supersonic needs, it would be possible to literally tear the aircraft apart due to the yaw. This can be stopped by installing a system whereby an outboard engine failure means an immediate automatic shutdown of the other outboard.
g. Frames 31 through 68 plus the review questions i the Theory of Flight Workbook (V-7021W) served asan excellent aid for this chapter. h. Modify tftggOlirplanes' your students built earlier andput control surfaces on them.Have a contest. i. Answers, to Chapter V Questions:
(1) that the forces arein. .(16) a. 3 b. 2 c. 1 bal`ance (17) More (2) a, 2 b. 1 c. 3 4
(3) a. 1 .1. 3 c. 2 (18) False u
(4) False (19) b. left.
(5) Stability (20) The Frise aileron
(6) a. 3 b. 1 c. 2 (21) Moveable control surface attached to.the vertical fin (7) The tendericy to return to an original position with (22) False a minimum of oscillation (23) False (8) c. longitudinal r (24) b. 220 (9) Behind (25) Stalling; maximum (10) The slight downward move- ment given to relative (26) Time wind passing over an air- foil (27) Service
(11) SlipstreaM (28) d.' weight
(12) Lateral (29) The angle between the aircraft wings and the horizontal (13) d. all of the above
(30) a. 1 b. 2 c. 3 (14) False (31) t6 correct for adverseyaw (15) More (32) "get thastick forward!"
1-44 FEBRUARY 1975
6. _INSTRUCTIONAL AIDS:
a. Films:
(1) USAF SP 1151 Crossover, 15 min., color, 1963. *** C TF-1-000 Airplane'Structures- Control Surfaces, 7 min., B&W, 1943. *
TF-1-4805 How an Airplane Flies; 34 min., B&W, 1953. *
TF-1-5300 Beyond the Stick and Budder, 14 mint, B&W, .: 1489 ***
TF 6129 Control Is ,a Greek Named Alpha, 20 min., colors 1967. *
TF 6155 F -4 Flight Chatatteristicss 18 min., colors.1968, .**
(2) FAA
FA-07 -03 Flying Boats, 10 min., **
(3) NASA -
NO.205 Space in the Seventiess. 28 mine, color, 1971.
b. transparencies
V-1008B Airplane Roll, Pitch, and Yaw Axes
V-1009 Operation of Elevators
V-1021 Take-off Conditions (not issued since 1971)
1V-1055 Runway and Approach Lighting System (better for V-7204)
V-1064 Control of Airplane4,in Plight
V-1066 Attitude and Attitude Control
V-1067 Control Devices 4 c. Slides) -' -0087 slides 14 through 20 J 4.
I-45 5 THEORY OF AIRCRAFT FLIGHT Handbook FEBRUARY 1975
d. Miscellaneous
(1) "Controlling an Airplane"- JAM HANDY filmstrip No. 2.
(2) Demonstration Aids for Aviation Education, CAP,pp 14-16.
(3) VCS, Visual Communications.Systems by William Reynolds- The plans for a moveable control model 'airplaneare on page 17.
(4) Small airplane demonstration models with moveable controls. These can be made in youlshop or purchased quite,inex- pensively through commercial sources in eitherpaper or plastic versions.
(54. "U; ,Fly-It" Aircraft Model.- ModelPiper aircraft on a glide line with a control stick for landings. Available
through Schaper Manufacturing Company, P.O.. Box 1426, Minneapolis, Minnesota 55427.
(6) Flight Simulators. Your School Boardmay be willing to purchase one for your school. Several excellent models are available for sale or lease through commercialsources. Prices range from approximately $1,000 Upward. Advise AFROTC/JRC if you are unable to locateinformation about simulators.
7. PROJECTS:
a. See page,81 in the text.
b. Have your students research and report on elevons, V-tails etc., and how they are used in aircraft control.
8. FURTHER READING:
a. Aircraft in Flight, CAP. PA
b. Current copies of Aviation .Week and Space Technology. .
c. VFR Exam-O-Gram.No. 28 "Factors Affecting Stall Speed."
d. The TUSC News.
7 1-46 0,1 IDEAS FOR IMPROVEMENT OF THE EXTBOOK AND/ORINSTRUCTOR'S GUIDE AVID TEACHINGTECHNINES ST. EFFECTIVE ',FOR THIS CHAPTER. TO' BE. 'COMPILED. AT END QFTEXT NW SENT TO 3-RC `, . I .THEORY OF AIRCRAFT, FLIGHT
. .,-,.
f. O
11
4 FEBRUARY 1975
CHAPTER VI - AIRCRAFT STRUCTURE
,
This chapter examines the aircraftitself. The major structural elements of the.aircraft provide a good framework fordiscussions of stress, constriction, and operation of selected aircraftcom- poneflts.
q 1
1' 1. I . a. jra itional - Each student should:
1 1(1) Know he major components of an aircraft.
(2) Know et least three types df stress-and their effJctson aircraft components.
.- , (3) Be familiar with at least three * types of elementary design .structures and howstheyare used to give aircraftcom- 0 Ponents strength without adding excessive weight,
(4), Know various types and t e...principatriarts of fuselages, wings, and empennage.
(5) Know the primary applications of "hydraulic and electrical systems in aircraft.
(6) Know how todays aircraft landing Oar works.
b. Behavioral - Each student should be able to:
(1) Describe thmajor components of an aircraft.
(2) List at least. three types of stress and discuss their effects on aircraft components.
(3) Recall at least three types of elementary designstructures and tell how th6y give an aircraft strengthwithout adding excessive weight.
(4) Discuss various types of fuselages, wings, and.empennage and describe the principal parts oeach.
(5) State the primary applications of hydraulic and electrical systems in aircraft.
(6) Descrpe,how today's aircraft landing ge4 works.
2. SUGGESTED OUTLINE:
a. The power plant(engine and propellers) 1110
I-V' 06, I RUARY 1975
(1) Housed in engine owling and nacelle/
(2) Engine toms prO eller
(3) Propeller create thrust, CNewton's 3 d Law of Motion) b. Fuselage
(1) Main part Of aircraft
(2) Hous\escrew, instruments, and payload (cargo, passengers, etc.)
(3) Two'm in types of fuselage construetion
(a) elded steel truss .(stee 1.11b)
(b) S mimonocoque (internall braced metal skin)
.(4) Five stresses acting on anal craft\inflight (stress is an internal frce which resists applied outside force)
(a) Tension: Stress which resists attempt to pull apart (like st etchin a rubber bald - or the pull on the control ables f an aircraft as you move the stick)
1 (b) Compression: Op osite of tension- resists a force trying to push gether (like squeezing a football from both ends-, landing gear struts undergo com- pression)
I
(c). Bending: Combination of tension and compression- wing span (interior structure) undergoesbending. during flight- lower side of spar' is subject to tension while upper-side is subjectedto compression
(d) Shear: Type of stress exerted when two items, such as metal bolted or riveted together, are puller apart or pushed together by slidingone over the other. Bolts and rivets are designed to resist shear
(e) Torsion: Stress which resists being twistedApart (torsional force is produced whenyou turn the steer- ing wheel of an automobile- or when the aircraft engine exerts a torsional forceon the propeller shaft directly affecting the flightof theplane)
' (5) General effect of stresses:
(a) All parts of aircraft are subjected,toone or more stresses
I-48 4 4 .
FEBRUARY1975
1 (b) Usually act in combinations of two or more
(d) Sometimekalternate: tension followed by compression,
etc. !
(d) Some pits carry only one type of stress; e.g., wires and, cables can carry only tension
(6) Trussed fuelages (used mostly in light civilian aircraft,
liaison, oservation, and training planes) f' $ f (a) Weldd tubular steel structure
(b) Coved with fabric over fairing (streaml ned)
Acts like the 'structure of a bridge
(7) Semimonocoque (used in most military aircraf
(a) Skin (usually sheets of aluminim alloy) and internal bracing carry the stress
(b\ ) Easy to build in streamlined forM
(c) SbLength comes from' metalskin reinforced by internal \rings and stringers
(8) Load factor; dad placed on aircraft under variouscon- dition of fright:
(a) L41: Aircraft is flying straight a dlevel and load is evenly balanced
(b) Strain: climbing, diving, banking, t rbulent weather
(c) Ultimate load: point of structural f ilure; usually 1 1/2 times the greatest load the ai raft structure 'will be subjected to in normal flight
(d) MaXimum appliedload - greatest load expected in flight
(e) Safety factor- ratio between maximum applied and ultimate loads
(f) Idea is to keep stress on any part froM reaching ultimate load, while keeping the aircraftas light as possible
1-49 FESRUARY'1475-' c. Wings
(1) Basic construction materials used are wood (covered With fabric) and metal
(2) Wooden wings
(a), Two long spars
(b) Curved ribs
(c) Spars and ribs are covered with painted fabric
(3) Metal wings
(a) Construction similar AO wooden wings, except ribs and covering are made of light metal
(b)/ Stronger,but heavier and more'expensive than wood
(4) Atta hment of wings to fuselage
(a) Full cantilever wing- very strong, can be ttached directly to fuselage without external bracig, used mostly by military aircraft and commercial airliners
60 Semicantilever wing '- internal structureo wing lighter, streamlined wires or tie rods correct wing
, to fuselage
(c) -Externally-braced wing- lightest of wing structures, struts or spars extend from wing to fuselage, used mainly by slow-flying aircraft, sporting, etc. d. Empennage (Tail section)
(1) Vi al for stability
(2) C mponents
( ) Horizontal stabilizer- fixed front sect on, provides longitudinal stability
(b) Elevator - hinged rear section, control angle of attack,'hence controls speed
(c) 1Gertical stabilizer (fin)- fixed front s helps maintain desired direction of flight
(d) Rudder - hinged-rear section, offsets adversey w
'I-50 5) FEBRUARY 1975
e. Hydraulic system
. (1) Pascal's Law- pressure exerted anywhere on a confined fluid is transmitted undiminished toevery portion of the vessel containing the fluid
(2),Mechanical advantage
(3) Operates brakes, lowers landing gear, extends and lowers , flaps, controls propeller pitch
f. Electrical system
(1) ',Operates radios,navigation equipment, lights,etc.
(2) Generator cftarges storage batteries . .
(3) Magnetos provide current which ignitesfuel mixture, keeping jet or propeller aircraftengines working
(4) Electric motors help pilot startengines, operate many mechanical devices, and performnumerous tasks where power is needed
g Landtng gear
III/ . (1) Main functions
(a) Assisttake-pff
e43) Absorb shock of landing
(2) Fixed or retractable- retracting reduces drag
(3) Shock absorbers'.-. oleo strut
(4) Brakes
(a) Operate independently for right and leftmain gear
(b) Antiskid prevents locking
(5) Types of landing gear I (a) Conventional
(b) Tricycle
(c) Bicycle
ORIENTATION:
a. An airplane structure isa combination of related parts, frame- . works, and assemblies, all groupedint a heavier-than-air
1-51 60 FEBRUARY 1975 V
flying machine. To fly, it must have an aerodynamic;shap. This shape must be made of parts having a high strength-to- weight ratio and having balance for flight./o.be safe, the aircraft structure must withstand more force than just that imposed by its own weight. In general, airplanes are designed to withstand one and one-haf times the full or' . r maximum expected force.- r b. This it the practical portion where the theory, principles, forces, and controls actually take shape.The student should recognize this relationship and realize that aircraft design and structure is the functional application of the areas studied earlier.
.,_ 4. SUGGESTED KEY POINTS:
,a. Man did not fly sooner becpse he id not have *V-9005, pp 30-31 an adequate engine. After one wa devised, it
**V-9013, pp . more than kept pace With'the changes in the 108-109 airplane structure. Our main concern at this **V-9118, pp point is that the engine is necessary and capable 168-169 of producing sufficient thrust to sustain flight. **V-9156, pp 1-37 However, the size, weight, and'shape of the *V-9156, p 49 engine are important because they influence air- craft design and construction.
b. The cowlings and nacelles which cover the engine **V-9118, pp 167, no. only protect the engine, they also reduce '170-171 drag by streamlining the aircraft. ***V79162, pp 1-9-10 c. Many students have looked out the window of an airplane in flight and noticed that the wings *V-9013, pp 84-86 flexed. Airplanes are flexible, that is, a ***V-9065, p 28 certain amount of movement in the airplane is
; expected and dgirable. Because the, craft is constaWybeing subjected to air currents and bumps of4arying intensity and direction, some flexibility is necessary in order to prevent structural failure.
d. .The five stresses which all aircraft undergo con- **V-9013, pp 87-88 stantly while in flight are 'tension, compression, ***V-9065, pp 24-27bending, shear, and torsion. To a lesser degree, **V-9118, p 8 the students' automobiles, bikes, and skate **V-9156, pp 54-57 boards underga the sari* stresses.
e. The fuselage does much more than serve as a **V-9013, pp 95-99 compartment to carry things.* It must be strong ***V-9118, pp enough to support all the other aird'aft components 142 -146 and withstand exceedingly large,stresses. There- fore, a knowledge of trusses and stressed skin designs is very important to the aircraft builder.
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1-52 FEBRUARY 1975
f. The primary lifting airfoil of an airplane is * -90' 6-28 the wing. Wings are attached to an airplane in V-9013,.pp 88-95 a variety of locations and ways- full'cantilever, *V-9118, pp semicantilever and externally braced. 147-153 **V-9156, pp 40-46 9..Empennage, or tail assembly, of an airplane is composed of several parts, each of which hasa **V-9013, pp definite control function. Structurally these. 105-108 parts resemble' wings, but are much,less complex., The student should understand tits following basic control functions.
(1) Horizontal stabilizer- helps to proyide longitudinal stability
(2) Elevator - controls angle of attack or pitch
(3) Vertical fin helps maintain direction of /., flight
(4) Rudder - compensates for yaw in turning
h. Hydraulics are only one of many systems whichuse a mechanical advantage to help the pilot operate ***V-91181 pp 9-10, .and control the aircraft. Quite obviously, a 14 -16, 18-20, C-5 pilot could not manually raise and lower the 182-188 flaps and the 28 wheels on_ the landinggear. On today's aircraft, electrical motorsare replacing
, hydrulicv for many functions. The electrical motors use the same principles of mechanical advantage.
In'addition to the basic conventional,. tricycle, and /**V-9005,pp 29-31 bicycle landing gear, some aircraft use pontoons f**V-9013, pp 99- or the fuselage to land on water while others land 105 on snow and ice using skis. All,systems must *V-9118, pp cushion the landing shock and still reduce friction 155=156 Officiently for takeoffs-so the aircraftcan be- . ***V-9156, pp 50-53 come airborne.
5. SUGGESTIONS FOR TEACHING:
4.1411 a. Suggested time: 2-3-3
b. Because ilthis unit we are examining the aircraft itself,we need to sdlb the relationships Of its structures andhow they fit together. Keep in mind theajor principTes'already stated, and try to,get the student to a ply these principles.to his new learning experiences. One pproach is to lead the student through assigned readings and have him bring discussionquestions
I-53 62 ) FEBRUARY 1975
to class. A good guided discussion would certainly promote more learning than lecturing or other methods. c. Fok5 this chapter, an understanding of your students' interests an abilities is essential. While some students will be bored and disinterested, fo1- some students this could be the most interesting part of the text. If you recognize a specific interest in individual students, you,should make an effort to individualize the method of instruction for them. They could be as'igned time-consumim construction or drafting projects and reduce their homework requirements for other areas. d. You may want tospend some time on mechanical advantage. Students are almost always interested in demonstrations of the pulley, lever, gear, and the inclined plane. (Also, you mai( want to point out that the man on the left i'n Figure 63 lacWs intelligence in two ways. Not only is he not using a lever, he's also using el incorrect lifting technique which could lead to a hernia.) e. Comrarisons with familiar items are always effective. For example, (1) the landing gear can be compared to an automobile's shock absorbers, (2) the aircraft hydraulic and 'electrical systems also have automotive counterparts, (3) some cars now have antiskid (why'), (4) knives, grinders, can openers,,etc., offer excellent examples of stgesses, and (5) a wrecked auto- mobile (there's probably one Fn the auto.shop) offers a graphic description of stresses. f. Your more advanced students might be assigned some computation problems. They could compute the amount of work dorie by a lever or a hydraulic system. If yctu want t9 impress them, merely mention that an aircraft hydroplanes when its speed equals nine times the square root of the tire pressure. Then
ask them to compute the speed their automobiles would hydro- , plane (Question 5, page 105 of the text). g. A swers to Chapter VI Questions:
1) d. all of the above (13) false spar
(2) engine protection, aids (14) 3 b. 2 c. 1 engine cooling (15) to -give more stability (3) streamlined containers
for auxiliary engine (16) a.' 2 b. 1 c. 1
. systems (17) six pounds (4) fuselage
1-54.
6.3 FEBRUARY.1975
(5) a. 4 b. 5 c. 1, (18) two inches d. 2 e., 3 7(19) refer to textbook section (6) true . on electrical systems
(7) false (20) less
(8) light; strong; rigid (21) oleo struts
(9) simimonocoque (22 antiikid
(10) the load placed on the, (23) b. tricycle' aircraft in .flight (24) bicycle 461) a. maximum applied load as
(12) a.. 2 b. 2 c; 1. d. 2 e. 1
h. Student teXt assignment: read pages 85-107.
6. INSTRUCTIONALAIDS' 4
'a. Films:
(1) USAF -
TF-1-5300 Beyond the Stick and Rudder, 14min., B&W, 1959. ** .
TF 6332 Hydraulic Brakes -,,Principlesof Oppration, 22 min., B&W, 1967. **
(2) FAA
FA-602 A Plane Is Born, 27 min., color,1968. *** -
FAC-135,The,Wind Is Right, 28 min.,color, 1971.. **if' 1 FA-807 Plane Sense, 20 min., color,.1968. *
b. Transparencies
V-1001 Airplane Components-
V-1004 B-2, Tail Structure (notfurnished after 1971.)
Y-1052 Basic Hydraulic Fluid System
7. PROJECTS:
a. See page 105 of the text.
1-55 64 41
FEBRUARY, 1975 1
b. Build an airplane! Not as far fetched as it sounds, Naturally it should be done through the industrial arts, department. Plans 'are available from the Experimental.Aircraft'AssOciation, Air Education Museum, P. 0..Box129'; Hiles Corners, Wisconsin . ,.. 53130, .,.. . ," , c. Warren Truss as a shop project and test its strength. On a smaller scale, it can be conttructe ith tooth ids and glue.
d. Invite an FAA Ipsp ctor to explain t6 the lass .wha he looks for when making airworthiness inspections.
e. Sever aircraft systems Such as/spark plugs are duplicated (redu dancy). Have your students discuss this.
f. Construct .aircraft models of various airceaft: Have students repo t on the construction features.
8. FURTHER READING:
a. See page 105 of the text. ,
b. Aircraft in Flight, CAP.
d. Aerospace magazine.
d. Aviation Week and Space Technology (December 1?, 197.4, pp ,A1.8.49).
e. The TUk News.
NOTE: Refer to "Aircraft Design Calculations,"a supplement to this handbookby It Colonel'Darreld K. Calkins, USAF Retired), Wilson'High School, Florence, South Carolina "(SC-51).., This supplement is intended to integrate the materia]s taught in this text with more advaved aeronautical technology. Use it as a challenge for yofir more advanced students.
.1-56 6b. ..
.. IDEAS FOR IMPROVEMENT- OF THE TEXTBOOK AND/OR INSTRUCTOR'S GUIDE AND TEACHING TECHNIQUES MOST EFFECTIVE FOR THIS CHAPTER. TO BE COMPILED AT END QF TEXT AND SENT TO JRC
THEORY OF AIRCRAFT FLIGHT ,
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VAPTER VII- AIRCRAFT INRUMENTS
This chapter introduces the studentto aircraft instruments. After the student learns about classifyinginstrUment systems, he can then examine selected instrumentsand,their operation. Because later units examinesome of these instruments in depth, this .chapter provides onlya quick look at the entire instrument panel with emphasison flight control instruments. The student should finish the chapter'"nowingwhy aircraft have instruments and what informiponthe pilot derives from them.
1.- OBJECTIVES:
a. Traditional- Each student, should' :
(1) Dow. two ways in which aircraft instrumentsare classified and one example of each group:
'(2) Know what each class of instrumentsdoes and how it works:
(3) Know how at least three flight controlinstruments are
b. Behavioral Each student should be able to:
(1) Outline two ways in which aircraftinstruments are grouped and give' at least one example. for eachgroup.
(2) Detcribe what each class of instrumentsdoes and how it ,
(3) us-Discuss how at)east three flightcontrol instruments are.
2.(c SUGGESTED OUTLINE:
a. Aikraft instrumentsare no more complex to a pilot' than auto Instruments aretoa driver.
b. Early instruments
. (1) Airspeed, measured with windgauges
(2) Didn't really need altimeters andnavigation instruments
(3) Early fuel gauge
(4) Early attitude indicator
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FEBRUARY 1975
g. Instrument classification 4.
(1) By usage
(a) Engine
(b) Navigation
(c) Flight
(2) By principle of operation
(a) Mechanical - gyroscope operation
(b). Pressure
(c) Electrical. d. Engine instruments and what they.indicate
(1) Tachometer - engine speed (RPM)
(2) Temperature gauges- oil ,.cylinders, carburetorintake
(3) Pressure gauges- oil, fuel, manifold
(4) Fuel quantity gauges fuel supply e. Navigation instruments and what they indicate
(1) Airspeed indicator - airspeed
. (2) Al timeter. - al titude
(3) . Compass - determines direction of flight based on 360° ci rcl e
(4) bock- measures time f. _Flight instruments and what theytindtcate
(1) Al timeter - al titude
(2) Airspeed indicator - airspeed
(3) Turn and bank indicator (needle and ball)- evaluation of a turn in flight
(4) Rate of climb indicator - gaqi or loss of altitude
, '(5) Artificial horizon - attitude of aircraft
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3 ..0,R1ENTATION: '::4! f 4. . v:. , . . -.' .. , . ; a. .Thellii.ot. cann ittidequately and accuratelysense all ofthe .. -canditioni Of, airc raft-and of. fligt.. Engine status,. aircraft ettitude.,..ancr,tomponehtiriforrationmust be measu and.clearlyindicitectiThese.readinqsmust be extremely accurate:and .readily avai 1 able-A° the oil otf The 'foi Pot is absolutely dependentkop.thesdinstranents fOrsafe oper"atio 6f.t.h.e, engine and powerplant., .. , la . ''.. . . , b.Emphasis is onli.ght inst'ruitients because'navigation and . pressure instruments 'are covered i n other tekt's...
, . 4. SUGGE TED KEY POINTS:s, .., ., While they look complex; .aircraft instruments, are reely'quite..simple andgenerally-easily readonce **1/4162, p 11'114 they're underttood.Also, in matiengine,aircraft, . N...:.-engine instrumentis'are%.duplitatedfor each elnine. . Referring to the .center 'clUster of instruments in .F.i9ure 65A, there are really only eight -instruments - but they're dupliCateda'foutl-times:' Thiscluster `
..t. .- system Makes it very'; easy to detect;mal function * on one engine,-If-onsly .Instrument idifferent,, -- check ,further'. .. ' f l .. -:, 4 ft: ) . 1 . Aircraft inS,trumen* are classified interms of
their,...use or in termS,;,of,the principle underlying 1 ***Y-9118,PP their construction; Throughout your,lessonstress 244470 ' -:.that- what .the:instrumeAt tells .the .pi1ot,is more ..impOrtant than how--i,totOks. .Later in the course, i'f,appropriate,' the dt"tutotional.sfieldof instrU- Nent repair and desl*n 'can 1)? diScussed. . . .4. t)146 (1)Engine instruments '110e onlyone fun'ction, ***11:-9005, pp 59-60 . t9 letthe, pi kliow how theengineis ***V-9161,,pp 2-28, ofoerating.Foj1 -the recipeocatin engine,, 2-33-6" the tachometer, tbnineratunegauges, ,pressue **V-9162, p 15. .gauges , "and .fuel quantity gauges are general ly basic.A beginning student nay feel too much stress is- ,placed:on engine instruments until .you pgja but that,ounlike a car, you can't pull Ver and park whimthe engine quits. . (2)Navigation ins.aumentsare primarily to keep **V:-9187, pp NAV-1-2',, the-pilot from Offinglost.Theie will be R -1-4 discussed in more deta 1 in the navigation text. (3) .Flightinstruments aidhe-pilot in estabfisA-. ...it-9002,pp 2 3 6 - 2 3 7 ing the attitude of thai rcraft.An ex- .perienced pilot with. e'aid of some nargation
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'nstruments, need never see the utside of 'he aircraft exceptfor tak offdnd landing.
c. Severel flight insitru nts use g rosdopes in order / ***V-9118,pp 271-, to maintain a constant ref rence poi teven when 280 the aircraft is execu ing roba is aneuvers. **V-9156, pp 156- For this-reason, the igidi y in spa e feature 161 should be emphasized as wellas he act that out- ***V-9162, p 17 side disturbances such as magnet smhdo not 'in-
***V-9187, FL-13- fluence its functio/ing. 1 c 14 -----... f . A propeiqy banked level turn with theforces in ***V-9 90, pp 76- 7 balance is a coordinated turn. The pilot uses **V- 56, pp the needle and ball (turn and bank pidicator)to 16 -165 determin whether or not he'is making a proper ***V- 162, pp 54-57 turn. Rate of turn may, also be gained front the **V- 156, pp 92-94 artificial horizon. ***V 187, FL-13-17 e. Many instrumentsnstruments aid the pi of in determining **V002, pp (. whether or not he is ch g altitude, but the ,
227-228 . , two primary instruments re the rate of climb ***T-9005, pr61-62 (vertical speed) indicator and tht artificial **V-9161, p12 -16 horizon. Using the artifici I horizon, the pilot ***V-9187, p FL-7 can quickly tell the aircraf 's attitude whether he is turning, climbing, or.i escendi*
5. SUGGESTIONS FOR TEACHING: e . 1
1
a. Suggested time: 2 -2
b. The depth and meod of instruction will depend primarilyon .how well' your stu ents have grasped the principlesof flight taught ill Chapters I, III,I IV, and V. Opening with a review of the four forces of flight and aircraft motionand control is appropriate. You might,ask your students which of the four forces apply to a baseball pitcher'scurve ball and then ask them to explain hbw. Most of them will quickly it recognize thrust, and weight. Some will say lift, but few will realize thaf it'spressure differential lift that causes the ball to cu ve. Because the ball is spinning, the relative wind is faste on the side rotating forward, or thereby reducing the press re and lifting (displacing)the ball in that Orection. er---7 4 / c. You should use a "hapds on" approach for thischapter. A flight simulator is he best possible instructional aid for this chapter, A poor man's alternative is transparency N-1011. An,exceIlent approach i% to turn off theoverhead, adjust the instruments, then turn it backon and have the students identify the aircraft's attitude,speed, altitude, etc.
.1-60 0 FEBRUARY 1975
d. This chapter presents an outstandingopportunity to review and reinforce the forces experienced in.a turn studied in Chapter V. Here again, you can use V-1010 and ask the students to draw the correct turn vectorand resultants based on the instrument readings.
e. The most effective way to explain a gyroscope and its characteristics is to actually operate a gyroscope. Ify do not have one, the science department will almostsure be able to loan you on A word of autjon,. your is _, .may well have alreadytudied gyroscopes 'recently and you then will merely want cover its importance to a study of aircraft instruments.
f. Instrument and control arrangement in the cockpit isa science itself.tself. A brainsfOrming session on where all the t ings in the cockpit sbould best be located should generatea
lively discussion. /
g. Answers to Chapter VII Questions:
(1)' true (19) navigation instrument
(2) piece of string (10) airspeed indicator and altimeter (3) engine, navigation, flight (11) lowest bank for th rate of turn (4) gyroscopic (12) g, h, e, a, 1,/b (5) rigidity in s ace and precession (13) rate.of climb indicator, .airspeed indicator, (6) false artificial horizon, altimeter (7) a. temp. b. pres. -c. both d. temp: e. pres.
(8) prevent fuel starvation, better lubri ation
h. Student text assignment: readlages 109-1 0
6. INSTRUCTIONAL AIDS:
a. Films: I.
(1) USAF
TF-1-5342A Instrumen.CFlying Technique,- Basic Instru- ments, 30 min., B &W, 1961. *
(2) FAA
FA-06-71 Dusk to Dawn, 28 1/2 min., color, 197T. ** s 4-6'01 4
FEBRUARY 1975
FA-09-03 Disorientation, 19 min., color, 1973, ** it FA 704 Stablt and Safe, 20 min., color, 1969. **
b. Transparency A
V-1011 Flight Instruments
c. Miscellaneous
(1) Gyroscope (V-2010)
(2) Flight Simulator (see page 46 this handbook)
(3) Homemade simulator - plans for building one plus a set of printed instrument faces can be purchased for approxi- mately $2.00 from: R. Brownsberger, 72 Parkway Aveque, Markham, Ontario, Canada
7 pROJEC S:
a. S e pages 120-121 of the text.
b.\ Hive a school photographer take pictures of actual airoatt_ nstruments and use them for display purposes.
c. i3et instruments from the bre salvage depot!
d.i Paint instruments'on the bottom of No. 10 can
e,. Inate an airline pilot a guest speaker o instruments in the modern aircraft.
8. 'FURTHER READING:
See page 121 of the text.
4aAircraft in Flight, CAP.
c. AFM 51-37, Instrument Flying AM d. AFM 51-40, Air Navigation
e. Private Pilot's Handbook of Aeronautical Knowledge,,FAA (AC 6)-23)
f. -VFR Exam-O-Gram No. 45, "Airspeeds and Airspeed Indicator Markings"
g. Commander's Digest, Vol. 16, No. 7, August 15, 1974, "How Simulators Aid service Training."
1-62
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IDEAS FOR IMPROVEMENT OF THE TEXTBOOK AND/OR INSTRUCTOR'S GUIDE AND TEACHING TECHNIQUES MOST EFFECTIVE FOR THIS CHAPTER. TO BE COMPILED AT END OF TEXT AND SENT TO JRC
THEORY OF AIRCRAFT FLIGHT
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